This guide aims to help anyone who struggles with combat in Thrones of Britannia. To ensure the information is also accessible for new players, I try to keep the information general. At the same time I also have to be detailed, my tactics are often designed around very specific, yet useful mechanics. Once you understand these, however, you'll see that many of my tactics are designed around the same few core mechanics.
There are probably other tactics that are just as effective (or even more effective) than my own tactics. I do not aim to provide the definitive combat guide, just one possible approach, so feel free to experiment, deviate, adapt, or discard my information.


What's the difficulty?:
The difficulty largely determines how heavily the AI responds to your moves. On the easier difficulties it will mostly attack head on and throw everything at you. While on the harder difficulties it will respond better (not perfectly) to flanking and diversions.
The difficulty level will also affect less obvious aspects of the game, however, like unit morale. Enemy units are more likely to break on easy difficulty than on legendary difficulty. Yet, this is only really noticeable when you suddenly switch from legendary to easy, as it will suddenly be so much easier to rout the enemy.

Legendary difficulty:
I have managed to obtain the achievement:
Glutton for Punishment
Complete the main campaign, achieving an Ultimate victory on Legendary difficulty by fighting and winning every battle.

I do not say this to brag (o.k. perhaps a little); but to preemptively counter any statements like: 'this would not work on legendary difficulty'. I have completed several campaigns (with various factions) using the tactics detailed in this guide, so they definitely work.

As a side-note, legendary difficulty is not nearly as daunting as the name suggests to be honest. I would argue its biggest challenge is 'realism mode' (see next topic).


Try it on other difficulties!
Realism mode will make the game much more enjoyable; especially if you tend to micro-manage every single action. I used to spend an hour on the most simple battles to ensure units did exactly what I wanted. However, with realism mode this is not possible, as you cannot issue any commands while paused. It took me a while to get used to, but now I pretty much always have it on. Realism mode can be switched on or off during a campaign (but not during a battle).


Verbose:
Yes I can be verbose, it's just the way I think and so write. Many a teacher has tried to remedy this, yet all have failed. I have tried to divide my extensive explanations into clear categories (although I am severely limited in this endeavor, by what Steam allows me to do in terms of layout). Nevertheless, feel free to scan the text for some useful information... there won't be any pop quiz at the end.

Sesquipedalian
My choice of vocabulary has also been described as archaic, excessive, unnecessarily difficult, etc., especially considering I'm not a native speaker of English (Yes, I'm even worse in my native language). I have tried to keep my language easily accessible to everyone, including those whose first language is not English. However, I might have failed in this endeavor occasionally (= I sometimes still use difficult words).
If this is the case, either
- use Google to look up a word you do not know and learn a new word, or
- point it out to me in the comments section so I can rephrase the sentence into something more easy to understand. Never feel ashamed for what you do not understand, just try to learn from it!

P.S. I used Google to learn the word 'sesquipedalian' today.

As the name suggests these armies are the backbone of my military. They are designed to take enemy cities and to fight strong enemy armies.

To achieve this my main armies are my largest armies and also contain the strongest units. I tend to put my king and his heirs in charge of them to minimise the risk of rebellion (you do not want to suddenly face these armies due to a civil war!).

They are positioned at my empire's frontier ready to repel any attacks or to invade at will. I obviously start off with 1 main army, and by the end of a campaign I usually have around 3 or 4 of these(the exact number depends on the size of my frontier) during the second half of my campaign.

While the exact composition of my main armies can differ between campaigns (based on a factions strengths and weaknesses), I try to keep them as identical as possible within a given campaign. This is so I can apply the same tactics to different armies without getting confused. At the end of the guide I will provide an example of an effective composition for each faction.


An example of one of my main armies during a Mide campaign

These armies are designed to defend my territory and support the main armies. As your territory expands, it will inevitably take longer for your armies to move through your land. This means that a minor 4-unit-rebellion or invading Viking army can wreak havoc deep inside your territory. Therefore the levy army is a smaller army of cheap units that will be positioned at strategic locations.

The value of the levy armies is best illustrated by a Mide campaign. Once you captured all of Ireland during a Mide campaign, your main armies will move across the Irish sea to fight in Scotland, England or Wales. This leaves Ireland vulnerable to viking raiders or rebellions.
Moving armies, or recruiting a new one, will take time (new armies will need to replenish first, or units might be unavailable). And so levy armies can provide a quick and cheap(-ish) solution to this problem. By having 2 or 3 levy armies positioned strategically in Ireland, you can quickly deal with any threats without halting your overseas expansion.

The levy units also work great in a supporting role for your main armies. While your main armies steamroll from city to city, your levy army can quickly take all the minor settlements to secure the entire province. This will allow you to expand much more quickly than with a just a main army.

The number of levy units is usually determined by my territory and frontier. Contested territory probably benefits from multiple levy armies in the area, while Scotland and Ireland can easily be defended by two well-positioned levy armies once they have been fully conquered. Yet this is the beauty of levy armies, as levy units are cheap and plentiful. This makes it relatively easy to raise a an army where you need it.


An example of one of my levy armies during a Mide campaign

Frequency: sometimes
Fun, but best to pick when you don't need any other followers.


Advantages:
- makes bodyguard unit stronger.
- could help get a general to 4 stars (to unlock night battles).

Drawbacks:
- Most of the advantages are barely noticeable. This follower will make your general unit stronger, but it does little for your overall army strength. However, while your general is undoubtedly a strong unit, it is unlikely to turn the tide of a battle if the rest of your army is weak. I therefore usually prefer other followers, as they have an effect on the entire army not just your general's unit.

Frequency: rarely
I don't really need him.


Advantages:
- higher income
- faster building time (at max level)

Drawbacks:
- Useless for generals. As far as I can tell, it only benefits governors.
- Govs assigned to well developed provinces will quickly reach 10 governance on their own. Furthermore, even without a scribe you can reach province incomes of over 4k. You simply do NOT need this perk to create a strong economy or manage provinces effectively.

Frequency: sometimes
This follower can be useful in some situations.


Advantages:
- Faster replenishment
- Slight bonus to zeal stat. A higher zeal stat improves public order.
- 10 fame bonus (at max level).

Drawbacks:
- This follower doesn't really have any drawbacks, as it can be very useful for certain characters. However, neither are its advantages incredibly strong. For example the +10 fame bonus at max level, is usually pretty much useless by the time you unlock it. Similarly, the added morale bonus only applies to the general's unit, which means it does nothing for the rest of your units. So while the bard might benefit particular characters in certain situations, it isn't a necessary follower either.


Frequency: rarely
While this follower can prove useful in early game, it usually becomes redundant pretty quickly.

Advantages:
- food production bonus
- lowers enemy food production
- immune to snow attrition (at max level)

Drawbacks:
- While the forager might provide a much needed food production bonus to your economy, I think it is not not an effective investment. Relying heavily on this follower would make your food production unpredictable (as characters can die). Instead I'd rather establish a reliable food production. Additionally, once you have a nice food surplus, this bonus becomes pointless. So, it will either endanger my economy if the general dies, or my general lives to a ripe old age and the bonus becomes useless anyway. I therefore recommend learning to play without him asap.
- The AI isn't limited by lower food production in the same way as we are, so this debuff seems to have very little effect on them.
- Depending on where you plan to send your general, this particular buff can either be completely useless or prove incredibly useful.


Frequency: often
This is probably my second-most favourite follower, as it provides several very useful bonuses.

Advantages:
- More supplies for you, fewer for the enemy. Your own armies will run out of supplies less quickly with this follower, making it very useful for sieges as well as sea voyages. At the same time it also lowers the supplies for enemies, which can be a nice bonus as the AI often has far too many supplies anyway.
- lower enemy morale. This means that enemy units will flee much quicker during battles. This can make a big difference in battles where you are outnumbered. This might prove especially useful during sieges where you are greatly outnumbered (whether you attack or defend), as units will often run away instead of fight to the last man.
- stops enemy replenishment(at max level). If a general with this trait enters enemy territory, their armies will no longer replenish in that particular province. This can prove particularly useful when the AI recruits a big army near you.
- extra income from raiding. Personally, I rarely raid settlements, so this is not really a bonus for me.

Drawbacks:
This follower doesn't really have any drawbacks.

Frequency: rarely
While this follower can be very useful, I rarely use it.

Advantages:
- extra campaign movement range
- reduced upkeep cost
- lower recruitment cost (at max level).

Drawbacks:
The reasons why I rarely use this follower are much the same as for the forager. I do not think it is an effective long term investment. Once your economy is up and running you do not really need the discounts, yet until then losing this general might prove ruin your economy. And while the movement range can be nice, it is rarely need for the way I play the game. I recommend learning to play without him asap.

Frequency: (almost) always
I almost always pick the priest' as my first follower! The only exception is for my faction leader & faction heir, because extra loyalty is useless for faction leaders.

Why this is my favourite follower:
- The added loyalty makes it much easier to keep gens & govs in check!
- The reduced movement for enemy armies is a great bonus as well. This gives you more time to prepare for attacks.
- enemy attrition (at max level). In my opinion this is the strongest bonus in the game. It causes enemy armies in that province to lose men every single turn as long as they remain in your territory! This means you no longer have to chase around small armies (because they will dissolve in a few turns on their own), and the longer armies wait before attacking, the weaker they become.

Drawbacks:
- The only drawback for the priest, is that the loyalty boost is useless for your faction leader. Hence why I do not pick it for my faction leader and faction heir (who will become faction leader eventually).

Frequency: sometimes
This follower can be very useful in siege battles, especially if you use catapults.

Advantages:
- longer siege holdout times for you and shorter ones for enemies.
- higher unit morale when under siege. This means units are less likely to flee during defensive siege battles.
- extra ammo & range for catapults (at level 4 & 5). This greatly increases the effectiveness of your catapults in siege battles.

Drawbacks:
- This follower is only useful for siege battles. The only exception to this is if you use catapults in your armies, then this follower will also prove useful in other battles (especially against enemy catapults).

Unit positioning:
The best default troop deployment is

• Infantry - front and centre
  
• archers - behind your infantry
  
• spearmen - on the flanks to protect your archers from cavalry attacks
  
• cavalry - slightly behind and on the outside of your spearmen so they can easily move around your army and attack the enemy.
  
• catapults - at the back of your army to keep them away from enemy flaming arrows.

Read the controls section (and advanced controls section) of the settings menu. This might tell you very useful controls such as:

• how to quickly group and un-group units together.
  
• how to increase a unit's rank / file (make them wider or narrower).
  
• how to make catapults attack a certain area, rather than a specific unit.
  
• how to move your army while maintaining their relative position to one another

I will not go over all of these controls here, as they are very easy to find in-game. It is also very much down to personal preference which features you'll use and which you won't.

Tip: Use hotkeys
Nevertheless I would argue that the more you can do with hot-keys, the better you will be. It is tempting to keep clicking with the mouse (especially to veteran gamers who have rusted into certain habits), yet by using keyboard combinations you can keep your mouse in the middle of the screen to select where you want units to be. This will save valuable time (especially in realism mode as you cannot pause to issue orders).

This is the most fundamental unit mechanic in this game, and probably one of the most important ones. The shieldwall ability makes units more resistant to missile damage.

And although it does not state so on mouse-over, I am pretty certain it also gives the units a general defensive bonus against enemy charges. Someone with more in-depth knowledge on the game-mechanics might correct me on this, however.


Lastly, the shieldwall button should not be confused with 'guard mode', as both have a shield icon. Guard mode (see icon below) simply means that a particular unit will not pursue enemy units when they flee, but instead will remain at their present location.



The wedge (as the icon shows), has your unit deploy in a triangle formation. This boosts their charge speed by 50% and provides 18 charge bonus. However, it also reduces melee skill by 25%, so you should turn the wedge ability off as soon as they have charged.



This makes the soldiers in a unit spread out, which should reduce casualties from missile fire. However do not expect the same kinds of results as shieldwall. It is most useful in reducing the number of casualties from catapult fire, especially if you deploy them in a broad line (rather than a column).

Although it is difficult to confirm, it seems it might also make cavalry move slightly faster through forested areas.


note: I pretty much only use archers, as I find skirmishers a waste of unit space. I suspect, however, that most of what I say here is applicable to them as well.

Fire at will:

Archers will automatically shoot on enemy units when they are within range.

Skirmish mode:


Personally, I barely use 'skirmish mode' as it tends to mess up carefully planned tactics by making missile units leave their hiding place, move away from friendly units (and get wrecked by enemy cavalry), etc. Yet there are 2 instances where I find the ability useful:
1. When your missile units are left without infantry / cavalry protection and have to fend off a single enemy infantry unit, 'skirmish mode' can be useful.
Rather than fight this unit and take heavy casualties, simply move your ranged units apart, and turn on skirmish mode. Now 1 unit can run while the other shoots, and if the enemy turns they will simply revert roles.
2. To draw away a portion of the enemy's forces. When multiple units follow a single missile unit (rather than fight the main portion of your army), simply turn on skirmish mode to make them run across the map and in the meantime your army takes care of the bulk of the enemy army.

Turn skirmish off by default:

If (like me) you hate it that your missile units break formation all the time (even when they are behind your shieldwall!), you can turn 'skirmish mode' off by default. Just remember to turn it on when you do want your missile units to keep their distance from enemies.

Just make sure that your missile unit runs away from the nearest battle-map border, as they will cause your ranged unit to stop (allowing the enemy to catch up).

Arrow types:
standard shot

"This is the standard shot type for this unit." -> just regular old arrows.

Flaming shot

This will make your archers shoot fire arrows. These arrows are highly effective against cavalry, but can also be used against other units to lower unit morale (I believe your own units can also be affected by this debuff).


This one is very obvious, it makes your cavalry units fight on foot.

I rarely use this ability. Instead I mostly find it annoying, as I sometimes accidentally click this one (when I want to click either loose formation or wedge ability), which suddenly causes your cavalry to stop dead in their tracks and slowly get off their horses.


This refers to a specific unit type (mostly axemen) rather than a specific ability. Nevertheless, the raider type units can be incredibly useful and it has some 'hidden abilities' that can be incredibly useful.

Gates:
Obviously the best way to break down the enemy gate is with a battering ram. This, however, is not the only viable method. Another good way to break down gates quickly is by using raider units.

In order to minimise gatehouse casualties, position your unit carefully before starting your assault. Don't just rush in!



Other (less effective) methods to breach a gate are:

• regular units - they can attack the gate just like a raider units, but raider units just do it so much quicker.
  
• catapults - I would not advise using your catapults to take down a gate, unless there is no other way. Generally catapults are not accurate enough to break down a gate, and will often run out of ammo before breaking it open.
  
• (fire) archers - It is possible to have fire archers shoot at a gatehouse, although the times I've tried it, they barely damaged the thing. So I would say their ammo is better spent on killing enemy units.

Towers:
Towers are among the biggest annoyances when assaulting walls (at least until you get catapults), and can cause quite a bit of damage to your army when left unchecked. However, you can use raider units to destroy the towers even before you breach the wall. Raider units (unlike regular units) only require a single volley of torches to set a tower on fire; even when it is raining!




You burned my town!:
The raider's ability to burn settlement buildings is probably their most well-known feature. Yet, the ability can also be an annoyance, as units positioned too close to a burning building when it collapses will take casualties. Luckily, Unit formations can help keep these raucous units in check.
- The shieldwall will prevent soldiers from running off to pillage and plunder. This is only helpful when defending a section of the town, as the shieldwall cannot move. Getting the shieldwall positioned correctly can also be tricky, as the formation sometimes jumps to a different position when individual soldiers are away from the unit.
- The wedge is the best way to prevent units from raiding the settlement. The downside to this formation, however, is that it is slower than the square formation.

Night battles block reinforcements from both sides taking part in the battle. This means that attacking during the night will allow you to fight opponents one at a time instead of all at once. Obviously this can be a tremendous tactical advantage.

As far as I know this is the only effect night battles have on the game. I have not noticed any change in unit behaviour during night battles (reduced visibility, etc.). Nor have I noticed any difference in unit performance (stronger or weaker units). Night battles do have some unique visuals (units holding torches), but as far as I can tell these are only cosmetic.

The option to fight night battles is unlocked when a commander has 4 or more command (the stars). The attacker decides whether or not to fight the battle at night, defenders have no say in this (obviously).

If a general is able to fight night battles a small check box will appear in the battle menu. Obviously a checked box will mean the battle will be at night.

Whether to fight a night battle or regular battle is usually quite simple. In most cases the battle prediction (red/yellow bar) will already let you know which option is best for you. Just in case you are still unsure which option to pick, I'll briefly explain how I usually decide which to pick.

Overwhelming odds:
If the combined enemy armies are much larger than my own, I will usually opt for a night battle.

In deciding whether the odds are too great I usually look at some of the following factors:
* unit numbers - While numbers don't tell you everything in this game, they do still provide some indication.
* unit strength - If they only have levy units and you only have elite and retinue soldiers you might still be able to beat them).
* terrain - This means looking at factors like walled settlements, bridges, forest area, to determine whether you're likely to out-maneuver the enemy. (The round button at the top right corner of the battle menu will allow you to see a preview of the battle map.)

In time experience will tell you whether a battle is beyond your capabilities or not. For instance if I'm faced with two full stack armies but it is a bridge-battle I generally know I'll be able to win anyway.

Reduce casualties:
Another reason to fight a night battle might be to reduce the number of casualties you'll take from the battle. So even if your odds are favourable enough without a night battle, fighting each enemy in turn will likely mean you take fewer casualties as your units are less likely to be flanked, and the enemy will flee much earlier.

When to avoid night battles:
Even if the odds are not in your favour, you might still want to opt for a night battle. Some possible reasons to do so are:
* taking care of two armies at once.
As I previously stated, there are times where I know I'll be able to win even if the predictor barely shows any yellow at all. In these cases I might opt to fight a regular battle rather than a night battle. After all beating two armies in one battle means you have one less battle to fight.

* prevent your ally from being wiped out.
Similarly if your ally is about to reinforce you, you might want to fight a night battle. The AI is a notoriously bad ally, as they will just rush at once (instead of grouping together). So, if you want to prevent the enemy from obliterating your ally, you might be better of fighting a night battle.

* you are going for the heroic victory achievements.
This will probably not apply to many of you, but I still wanted to point out the obvious. A victory is more likely to be counted as heroic if the odds are against you. Consequently, if your aim is to win as many heroic victories as possible, you might want to fight battles without reinforcements.

There is nothing you can do when the enemy attacks in a night battle. So if you are suddenly forced to fight a battle on your own (even though reinforcements were nearby) and you have no idea why, it is probably because the enemy has selected a night battle. This does not happen often, but can happen on occasion.

Illustrations still to follow


Surround them:
When attacking the enemy in open battles, try to surround them as much as possible. Very few units can withstand an attack from multiple sides for long, they will either break or be massacred quickly.

Use strong defensive units in the frontal assault, so the enemy is held in place. Then use cavalry, missile, and offensive units to flank them and attack their rear.

The enemy usually puts their strongest units at the centre, so working your way down the flanks will mean a large numerical advantage by the time you get to their strongest units. However, this only works if your defensive units are strong enough to withstand the enemy!
If they break before you crushed the enemy flanks, your units might easily end up being the surrounded ones.

Divide and conquer: (this tactic does NOT work if you have catapults in your army)
The following tactic is one of my absolute favourites in defensive field battles. Not only because it can be incredibly effective against larger and stronger forces, but also because it is Incredibly nuanced. The slightest difference in approach can make an incredible difference in the final outcome.
In fact, it took me an incredible amount of practice to perfect some of the stages of this tactic right. I've started battles over 5-10 times, just to test whether a slightly different approach would be more or less effective (or because some dumb unit broke hiding too soon or did not move where I wanted to).
This means I will only cover the general outline for this tactic, and you will be left to experiment and try things for yourself (but that's part of the fun of course).

Deployment:
In this approach you entire army needs to be hidden when you start the battle. To do this you hide your army in a forest at the side of the map and hide your cavalry (at least 2 units) in a forest at the centre of the map (but far enough back).That is also why this tactic does not work with catapults, as they cannot be hidden during the deployment phase.

If your entire army is hidden from the start of the battle, the AI will send units (cavalry if they have them, ranged units if they do not) to find your troops. Providing you with an ideal opening strike, as you can often destroy an entire unit (sometimes even multiple ones) while their main army is still well out of range. You need to use cavalry for this to work, however, as the enemy will recall their scouts as soon as one of your units are discovered. This means infantry will just be left to run after the enemy unit.

note: Finding the ideal way to ambush enemy units in this tactic will need some trial and error, so enjoy playing around with different methods.

Stage 1: Divide
Once your cavalry units are out in the open, split them to either side of the enemy army. This will cause the enemy army to divide into two groups, each following a cavalry unit.
Now move 1 cavalry unit towards your hidden army staying just out of range of the enemy, while you move the second cavalry unit in the opposite direction away from your army.

note: If you divide your cavalry in more than 2 groups your are just it difficult for yourself, as the AI is much better at coordinating multiple units than we are.
note: Make sure your cavalry units do not become hidden while you lead them around the map, as it will make the enemy regroup!

Stage 2: Conquer
Once your first cavalry unit has reached your own army you can start to fight. As soon your army is no longer hidden, either hide your other cavalry unit or have it run back to your army (if it is safe to do so). Either way, it is best to focus your attention on the main fight.
By the time the second part of the enemy army has reached you, the first will either have been defeated completely, or at least severely wounded and about to retreat.


Corner walls:
While this tip is not the most noble of approaches, it is nevertheless easy and effective. Deploy your army in one of the map corners to prevent the enemy from outflanking you; it's that simple. This tactic will allow you to hold off much stronger enemies.

If this sounds like a lame misuse of game mechanics to you, think of it like this. Real life generals used ditches, stakes, barricades, thorn bushes, etc. to create a similar effect. So, since we do not have the same resources as those generals, we have to use what is available to us.


Funnel the enemy:
By now it should be clear to you that the key to victory in this game is using any advantage you can get. Buildings (or the space between them) are another one of these advantages. Some field battles include a number of buildings on the map; especially those around minor settlements. You can use these buildings to prevent the enemy from outflanking you, or even attack the enemy from behind.

As there are too many different village structures, and a lot depends on the way both armies are set up, I will not be able to provide more detail on this approach. My best advise is to take the buildings into account when deciding your strategy. You will have to decide for each battle whether the best approach is to use buildings, forest, or a combination of the two to defeat your enemy.

Anyone with even the slightest knowlegde of military tactics knows that crossing rivers makes armies vulnerable. Rivers can only be crossed in a handful of places, and an army is forced to stretch out and break formation while crossing. However, this is also exactly what makes them incredibly useful for defensive purposes (more on that later).

So, how do you go about assaulting a bridge in ToB?
The short answer is you don't. Luckily for us, the AI is like an impetuous and inexperienced commander who can be made to fight on your terms. This means you can make him cross the river, rather than cross the river yourself. The following mechanic will help you achieve this.


Drawing them across:

• If you have catapults (and the enemy does not), making them cross the river is easy as they will switch to offensive mode right away and charge across the bridge immediately.
  
• If neither of you has catapults (or both of you have them), making your opponent cross the river takes a bit more time.

If neither of you outranges the other, you can still draw the enemy across the river by depleting the enemy's ammunition. This will effectively turn them into melee units, which in turn will trigger the 'come to me' mechanic. For this to work, however, you will need to hold on to your own ammunition until theirs is depleted. Keep your archers out of range until the enemy has run out of missiles. Once they've run out, move your archers within range to draw the enemy across the bridge.

Tip: Use the 'shieldwall' ability to drain their ammunition without taking too many casualties
(more on this in the next section).

Hold your horses!
An expression the enemy clearly doesn't know, because they will send their cavalry across the bridge first. They will usually run along the railing of the bridge and leave the bridge on the sides (possibly this is because they are programmed to deploy on the flanks).

To prevent this rash charge from working, simply place spearmen to block your side. Be ready, however, to protect your archers from any horsemen that managed to pass your spearmen. If you have cavalry (and you should), use them as they are pretty much useless until the enemy routes.

Bridge the gap
Putting your spearmen on the sides of the bridge will leave a pretty big gap for the enemy infantry to rush through and overwhelm your spearmen. Additionally, most spearmen do not have the strongest of shields, and so are quite vulnerable to enemy missiles.

Place one of your stronger defensive infantry units between the spearmen to take the brunt of the enemy attack. Position them at the same time as your spearmen, because the enemy infantry will immediately follow their cavalry.

Take cover
- the enemy will mostly fire at the nearest unit.
- position a shieldwall at the shore to draw enemy missiles
- position them behind a rock for even greater cover

Hit them with your best shot!
- catapults (just out of reach of enemy missiles, yet close enough for maximum accuracy).
- archers

Deployment recap:
You won't be able to position your units like this at the start of the battle, so you will have to act quick when the battle starts (or pause the game and take your time, if you do not have 'realism mode' on).
Nevertheless, your army should look something like this just before the enemy crosses the bridge:

With:
• strong infantry at the centre
  
• spearmen on the sides
  
• good defensive units at the river's edge
  (note how only they are targeted by enemy missiles, with a few stray arrows hitting the units behind)
  
• wedge infantry out of range from enemy fire
  
• archers just in range of your side of the bridge
  
• cavalry just behind your archers
  (to defend against any cavalry that make it past your spearmen)
  
• catapults near archers

Pincer them
use any remaining infantry to attack the enemy from the sides. Use infantry units with the 'wedge' ability at this point to devastating effect. If your units are losing and you need that little bit of extra manpower to hold the enemy, you could also dismount your cavalry and have them join in the melee. It is unwise to have them fight from horseback as they will likely take too many casualties.

No longer hold your horses
Once the main part of the enemy army has been routed, you can finally use your cavalry. Send them across the bridge to kill as many of the enemy as you can, to weaken the enemy army for any followup encounter.

Step 1: Land your naval units outside the town. Your cavalry & catapult units do not move, they are there to cause a distraction! If you do not have any naval units you deploy your units in the forest at step 2.

Step 2: Hide your units in the forest. Put your raiders up front, and place the archers behind to apply covering fire if necessary. Hide the remaining units behind.


Step 3: Use your raiding units to break down the top gate, and burn both towers from outside the settlement (see section 2.c for further details). As soon as the gate is down, move both raider-units inside to capture the gatehouse and prevent a bottleneck!.
Keep your remaining units hidden until both towers have been burned and you captured the gatehouse to minimise casualties.

Step 4: Move your infantry units into the town and secure it. Either by: moving towards the capture point at the centre, or killing all defenders.

Some cities have extreme bottlenecks further into the city (Bebbanburg / Edinburgh is a prime example of this). These bottlenecks can be used to great effect (especially when rain protects siege towers). In most cases, however, you'll be better off fighting at the walls; as the attackers are funneled into smaller areas, and the towers and gatehouses provide additional support.

Use archers to burn down as many siege towers as possible, and ignore the ram (they can always just break the gate down without a ram, so it's a waste of arrows). Disable 'fire at will' & enable 'fire arrows' to prevent wasted ammunition.

Have all archer units target the same tower, as you don't want 2 towers with 80% fire damage to reach the walls. Instead it is better to have 1 tower burn down and the other to reach the wall.

If rain prevents the use of fire arrows, keep your archers away from the wall and save their arrows. Once the towers have landed, hold the enemy in place with some melee units, and have your archers hit the attackers in their flank to inflict heavy casualties.

Place melee units where you expect the surviving towers to 'land', to slaughter the enemy as quickly as possible. Place your spearmen behind the gate to hold the enemy once they break it. Make sure you have enough units within the gate's circle to maintain control of the gatehouse and towers.

Positioning a melee unit just in front of the tower (but not on the wall) in shieldwall formation can be a great way to draw enemy fire. This should lead to fewer casualties among your ranged units, which in turn means they can do more (fire)damage to towers/enemies.

Cavalry units are not generally included in a city garrison. However, cavalry units could still be included in your defending forces. In that case, you should position your cavalry at another gate (where the enemy will not attack) so you can move them out of the city as soon as the battle starts.

Hide them in a nearby forest, and once the enemy infantry is engaged in the assault, you can use your cavalry to ride down the unprotected missile units. Once the ranged units have been defeated, you can position them just outside the gate.
Do not charge them into the back of the enemy as long as you control the gatehouse, as your cavalry might take massive casualties from the boiling oil!
If the enemy has taken control of the gatehouse, you can charge into the bottleneck to massacre the enemy, otherwise it is probably better to wait outside and just use the cavalry to ride down any routing units.

• Very strong defense
  
• Strong sword

• Infantry units:
  -
  
• missile units:
  -
  
• cavalry:
  - 2 x cavalry
  
• catapults:
  - 2/3 x catapult

General unit up front to catch incoming arrows (not once the general unit is upgraded, by then strong sword units should be able to tank missiles).

Have sword infantry slightly behind general unit to engage enemy in flanks as soon as the enemy attacks the general unit. (they usually go in large force for the general, so be ready to aid him).

Either position missile units behind infantry with spearmen on the flanks to protect them against cavalry, or hide them in forests to the sides of you army (again accompanied by your spearmen to protect against cavalry attacks) so they can fire into the enemy from the sides or even behind.

Use a few cavalry units to move around the enemy and attack their missile units. Once you cleared those you can charge them into the back of the enemy infantry and break their morale quicker.

• pin and flank (infantry)

• Infantry units:
  - 2 x spearmen
  - 6 x swordmen
  - 4 x 2h axemen
  
• missile units:
  - 3 x archers
  - 2 x catapults
  
• cavalry:
  - 2 x cavalry
  - 1 x general unit

My main armies during a Mide campaign on legendary:

My levy armies during a Mide campaign on legendary:

note: this screenshot is from the very end of the campaign, so the cheaper levy units had been upgraded to retinue units (as money and availability were no longer an issue). Do not waste expensive units on your levy armies from the start! Only once your main armies are fully equipped should you 'upgrade' your levy armies.

• Infantry units:
  -
  
• missile units:
  -
  
• cavalry:
  -
  
• catapults:
  -

• Naval combat
  
• strong (axe) infantry

The Sea Kings' main strenght lies in their strong infantry units. Their regular shield retinue are strong warriors capable of holding a line, while their 2-handed axe units and beserker units are incredibly strong flanking units capable of routing units very fast.

• Cavalry
  
• Archers

While the Sea King cavalry & archers are not necessarily the weakest in the game, they are not as strong as for instance Welsh archers or Gaelic cavalry. Relying heavily on archers and cavalry is therefore not advisable. Instead it is probably best to have a couple of cavalry units to flank or chase enemy units, and a few archer units to target enemy missile units.

All this means that a strong Sea King army relies on it's infantry units to do the heavy lifting. While employing some ranged and cavalry units to overcome any units that are difficult for melee infantry to fight (skirmishers & cavalry).

• Infantry units:
  - 2 spearmen units (1 for each flank)
  - 4 - 6 shield units (axe or sword retinue)
  - 2 - 4 offensive units (2 handed axemen or berserkers)
  
• missile units:
  - 3 archer units
  - 0-4 catapult units (this very much depends on how much you like catapults.)
  
• cavalry:
  - 2 cavalry units

Don't run from naval battles:
Naval battles are best avoided for most factions, because you'll often end up losing too many men even when you win.(as tends to happen when an entire ship sinks). However, the Sea Kings are the exception to this rule! They are the only faction without the naval battle debuff, meaning they are stronger than the other factions. This allows you to hit enemies much harder on the water than on land, and can overcome much stronger opponents.
Despite this big bonus I still dislike naval battles, so I mostly go for auto-resolve if the odds are sufficiently in my favour.

Flanking:
When fighting land battles as the Sea Kings it is essential to flank your enemies with strong offensive units. This will cause the enemy to route quickly allowing you to inflict heavy casualties while minimising your own casualties. The wedge ability will definitely come in handy for this (both 2 handed axe units and berserker units have this ability).

The main difficulty will be in shielding your offensive units from being charged by the enemy.
- Deploy your shield units in a broad line with your offensive units behind.
- As soon as the enemy hits the first line, you start moving your offensive units to the flanks to try and encircle the enemy infantry.
- At the same time use your cavalry and archers to kill or chase off the enemy missile units to protect your infantry from being shot in the back.

Alternatively hiding offensive units on the flanks can allow you to hit the enemy with a devastating "broadside" (i.e. attack them from a single flank or from behind with 3 or 4 units).

• death from afar! (ranged)
  
• ride them down! (cavalry)

• Infantry units:
  - 4 x sword infantry
  - 2 x axe infantry
  - 2 x wardogs
  
• missile units:
  - 4 x longbowmen (unlock this technology quickly!)
  
• cavalry:
  - 2 x elite cavalry (border scouts until you unlock the elite cavalry)
  
• catapults:
  - 2/3 x catapult (can even go up to 4 catapult units at a later stage).