If you are struggling to marry a character, try to subjegate a faction instead of destroying it. This will make them become your vassal. Once they are your vassal try to marry your character to one of theirs. As far as I can tell this makes them more likely to accept the proposal.

Subjegating a faction counts as negotiating peace.

Before you declare war on everyone you can first sell some declarations of friendship to other factions. This can easily provide you with a 1000-2000 gold bonus in your first turn. As you plan to stay at war the entire campaign anyway, it does not matter whether you are unreliable or not.

Another option is to attempt to sign a military alliance with a trustworthy faction. Then declare war to all other factions (which they will join) before breaking the alliance. This can be very helpful in the early stages (when all factions will send armies your way), as this gives them another enemy.

I got this achievement with Sudreyar on easy difficulty. Apart from the military alliance with Orkneyar that you already start with, I also signed a deal with Gallgoidel (directly south of me). This way I had a faction who was also at war with (almost) all other factions on either side of me. They drew a lot of armies away from my precious starting provinces.

I'd started the same campaign before, and I had sold as many declarations of friendship as I could. I ended up with over 8000 gold (starting money was 6000, no idea whether that's due to easy difficulty or a Sudreyar thing). However, I soon got overwhelmed when 5 or 6 big armies landed near one of my towns (and more kept coming), and although I could stop them from taking my cityI couldn't finish them off. When they all started raiding my economy quickly collapsed and I decided to start over with the military alliance method.

to be continued I guessI ended up completing this achievement by reverting to the launch version of the game. Back then the achievement required you to complete a campaign with your War Fervor never falling below -12. I managed to complete a quick Gwined kingdom victory on hard difficulty.

I easily got this achievement on very hard difficulty with Northymbre. You start with 2 relatively strong vassals, and its 'short kingdom victory' is very easy to obtain.

It seems this achievement cannot be obtained when:
- your enemy is destroyed by another AI faction. So try to engage in conflicts with small factions so you can quickly subjugate them into submission, before anyone else can destroy them.
- you cancel 'vassal status' for any of the defeated factions. Keep vassals alive and under your command.

Gwined is probably the best faction to obtain this achievement, due to their easy victory conditions. You just have to control the entirety of Wales to win the game. Nevertheless I had to try several times on legendary (don't ask me why I decided to try this achievement on Legendary). Even when I got fed up with trying on legendary, and switched to easy, it still took me several tries. This is why I would advise a lower difficulty, to allow multiple save files, so you can revert to an earlier point in the campaign.

There are 2 things to watch out for:
- Mierce --> It can be difficult to subjugate Mierce if they take any Welsh territory. So it is best to either let the other Welsh factions retake those areas before you subjugate them. If this is no longer possible, you can either attempt to subjugate them, or revert to an earlier save.
- West Seaxe --> There are two vassals of West Seaxe in Wales. These will declare independence at some point. However, the moment they do that seems to be random. Around turn 50 in one of my legendary attempts I controlled all of Wales except for one of those faction's areas. By the time I got to turn 135 one of them still hadn't declared independence.

It requires a bit of luck since rebellions are random (to some extent) and you could run into negative food between turns (if enemies take your food villages). So don't be discouraged when it takes a few campaigns (you'll have to do plenty of them anyway if you want to go for all the achiemements).

This one also requires a bit of luck since rebellions are random (to some extent). It is possible to prevent civil war (usurpers) if you keep an eye out for low loyalty, and prevent units from hitting 0 loyalty during turn switch.

This one is easily obtainable on easier difficulties. On Very Hard and Legendary, characters automatically obtain a -1 loyalty bonus. That means maintaining a +2 loyalty throughout the campaign is very hard, especially in the beginning when funds and estates are limited.

To get this achievement your general needs to obtain the 'Dreaded attacker' (lvl 3) trait - Heroic Victories when attacking. My explanation and tips on how to get this particular trait under the "Hard pressed" tip below.

To get this achievement your general needs to obtain the 'Heroic Defender' (lvl 3) trait - Heroic Victories when defending. My explanation and tips on how to get this particular trait under the "Hard pressed" tip below.

While getting the traits for both achievements was relatively easy, it seems that generals cannot have both Legendary traits at the same time. This means I have to 'train' another general to get the defender one.

I would recommend going for this achievement on hard difficulty at least, rather than on lower difficulties. In order to get these achievements you need to get the trait for "Winning a Heroic Attack/Defense" to level 3.

Enemy armies are less aggressive on easier difficulties and my tactic for both "Legendary Defender" and "Legendary Attacker" is build around being attacked by strong armies.

Getting Heroic victories: (This is based on my personal observation, not on game data!).
To determine whether a victory is seen as Heroic or Decisive, the game seems to compare each army's size. However, the 'army size' value seems to be based on the number of men, as well as the number of units on each side.

This means you can easily achieve Heroic victories (either attacking and defending) by having an army that only consists of the general's unit. You can garrison this army inside a city to defend the town against large armies. Once you've beaten the attackers, you can use the general unit to take out the surviving few stacks.

Beating these armies will count as Heroic victories as long as they have multiple units; even if you have more men! (as can be seen on this screenshot) https://test-steamproxy.haloskins.io/sharedfiles/filedetails/?id=2188233640

My approach:
Playing as Mierce, I decided to send a strong army to Ireland ASAP (somewhere between turn 10 & 20) to capture Dún Pátraic. This allowed me to unlock the Research part of the tech tree very early, but more importantly (for these achievements), it created a 'bait city' for the AI. Since the AI usually attacks the town closest to their own territory, the AI regularly sent large stack armies to the town, yet ignored my remaining territory.

Once I had captured the city from Ulaid I made peace with them to strengthen the town and let the garrison replenish. By the time this was accomplished Ulaid had been defeated, so I declared war on Aileach (and so their vassal Airgialla) and Sudreyar (and their military ally Orkneyar).

I found Dún Pátraic to be an excellent settlement for this purpose, as the town has only 1 gate. This means the entire army (and any reinforcing land armies) are forced through a single gate. They might also deploy several towers, yet with 3 or 4 archer units you should be able to burn at least 1 or 2 of them before they reach the wall (and it doesn't rain).
It does have large stretches of beach area where amphibious assaults can land, yet I barely had any amphibious assaults at all. Instead most armies came over land from the north.

This one seems to be triggered by winning enough heroic victories. This achievement can be obtained on easy difficulty, where winning heroic victories shouldn't be that big of a deal. Or you leave it until you go for "Legendary Attacker" or "Legendary Defender", as you will win enough heroic victories there too. it seems characters cannot have 2 legendary traits at once.

In order to get this trait, you need a level 10 governor with the following 3 traits:

• Authoritative (level 3) - gained from having 10 influence
  
• Bountiful (level 3) - gained from not having food shortages
  
• Peacekeeper (level 3) - gained from +10 happiness

This one caused me a lot of headache as my governors kept dying of old age before they got this trait. Either they would not be level 10, or they would miss one of the three required traits.

In the end I 'trained' my governors to max level quickly by making them generals. Towards the end of your campaign, generals will have several buffs that give them XP each turn. They also get XP for taking towns or defeating enemy armies. While leveling this general up I would pick traits that would prove useful as a governor, rather than a general (e.g. scribe, bard, forager, etc.).

Once a general was level 9 or 10 I switched them to governor. I would assign him to a province with at least +10 happiness (without a governor) and 100+ food. In most cases these characters would have max influence already, but in case they didn't I would give them some estates to increase that as well.

I tried this approach with a substantial number of generals, and in the end my king was the one to have max level and all 3 traits. It took a few turns for him to obtain the legendary governor trait.

A governor can obtain this trait by having the following buildings in its city:

• Forge
  
• Arena
  
• Garrison

Once the buildings have been built (do not need to be max level), the governor will obtain the trait eventually.

Found this out through a comment by Daruwind.

This achievement does not require you to capture any regions, but rather hold on the ones you started with. Pay special attention to the minor settlements, as they can be taken without a battle.

There are 225 regions in total. You should be able to focus on your economy the first 30-50 turns, and then starting to focus on conquest. Up until turn 50 I took less than 1 settlement per turn on average. Between 50 and 80 I started to conquer more and started to take an average of 2 settlements per turn. Around turn 100 I had just over 100 settlements, but by turn 120 I had already around 150 areas. So there's no reason to start panicking if you don't take a settlement every turn, or even every two turns at the start.

I did this during a Sudreyar campaign on easy difficulty. I definitely recommend Sudreyar for this achievement for 4 reasons.
1) Strong military units.
2) no sea-battle debuff.
- This provides a huge bonus when fighting sea battles (or amphibious sieges), against everyone except other sea-king factions.
3) +15% campaign movement speed.
- This faction-buff allows you to move armies around much quicker.
4) starting location.
- You start with a monastery building in your city, which means you can quickly unlock the research branch in the tech tree.
- Also, by starting all the way in the north you can sweep your armies south, only establishing the occasional guard army to defend against viking invasions (which are relatively rare on easy difficulty).
- Finally, by starting way up north you have more distance between your neighbours at the start. This means you can more easily defend against enemies. By the time you reach the more densly populated southern areas you'll have strong armies to quickly take many settlements.

Rock of Caisil

Caisil (Southern Ireland)

Mountain Hall

Eidenburg (Scotland)

Offa's Hall

Tamworthige (Middle England)

There seems to be very little information on this achievement. I could not find the exact settlements on this list. However, you should get this achievement anyway when you go for the Speedy Subjugation achievement (Playing as any faction, conquer all regions on the campaign map in less than 200 turns). So it's probably no use in going after it specifically.

Trivia: Nennius' list is a medieval listing of 28 cities in the British Isles. The problem with this list seems to be that it is not always clear which cities they refer to. So even looking up the list proved to be of little help. Nennius' list (version 1) [www.earlybritishkingdoms.com] Nennius' list (version 2) [www.caerleon.net]

St. Ciaran

Cluain Mac Nois

Central Ireland

St. Patraic

Ard Macha

North Ireland

St. Brigit

Nás

Central Ireland

St. Columbe

Dun Cailden

Central Scotland

St. Swithun

Wintanceaster

South England

St. Dewi

Menevia

Wales

St. Ringan

Hwitan Aerne

South Scotland

St. Cuthbert

Dunholm

North England

St. Edmund

Sancte Eadmundus

South England

Hylmrekr

West coast of Ireland

Corcach

South-west coast of Ireland

Vedrafjordr

South-east coast of Ireland

Veisafjordr

South-east coast of Ireland

Dyflin

East coast of Ireland

Castletoun

Isle of Man

As I saw some forum posts about people wondering how to get this one, I thought I'd share how I got this achievement. I got it when defending a coastal town against 3 full stack viking armies, 1 via sea and 2 over land. My own forces consisted of the town garrison and a full stack army. (Due to the max level priest trait for both general and governor, the units in the two land armies were severely weakened before the battle).

- Catapults:
I put the 2 catapult regiments from my army at the coast together with a couple of strong infantry units and some javelin throwers. The catapults took out 90% of the fleet before they even managed to get on land. My infantry units quickly overwhelmed those that did.
- Archers:
On the other side of town I put all my archer regiments (5 in my case) on the wall to shoot fire arrows at their siege towers. This way I managed to set all (three) of their siege towers ablaze before they reached my walls. (This part will not work if the enemy attacks during the rain). if they attack during the rain, you'll have to either also defend against the siege towers, or see if you can bottleneck them anywhere else in the settlement.
- Gate:
This only left the battering ram, I had already positioned my strongest regiment in shieldwall just behind the gate, with all my levy spear-regiments behind it. This holds the enemy at the gates, and lets the towers & boiling oil do the rest. Note that while 1 or 2 strong regiments can already pretty much hold back an entire army at the gate, you need to have enough troops at the gate to prevent the enemy from disabling the oil and towers.
-Cavalry:
During the deployment phase, I had positioned my cavalry (2 regiments, governor, and general) at a different gate. Once the battle was on its way and the main gate was breached I rode out of the second gate and positioned my cavalry outside the besieged gate. This step was not needed to win the battle, but I used them to run down fleeing soldiers. (Be careful you don't run your cavalry into back of the soldiers attacking the gate. The boiling oil is highly effective against cavalry).

Losing minor settlements does not count as a battle, so focus your armies on protecting your major settlements. Once the enemy army is defeated, you can retake all the minor settlements.

Hiring a general with one or two cavalry units can help you take small towns in quick succession. They can travel further than armies with infantry units. Be careful where you move them however, if they are forced into battle they are very likely to loose.

Note: This tactic is not very suitable for factions where the general fights on foot, since this means the general's unit counts as an infantry unit.

It is possible to obtain all battle achievements on Legendary difficulty. So for those of us who dislike playing battles manually. Obtaining these achievements during a legendary playthrough, can be a helpful way to reduce the number of manual battles one is required to play. Due to the limitations of legendary-difficulty, however, this tip is probably only useful to those few who are good enough at battles that they are bored by most of them.

For tips on playing battles on legendary difficulty see my tips below

The game auto-saves at the end of turns, the beginning of turns, and at the start of a battle. This means you have to be careful when moving your armies, as it is not possible to load an earlier save file once an army attacks you. However, this also means the game does not save until the battle is over. It is possible to Alt+F4 out of the game and restart the battle. So as long as there is a chance of winning you can restart the game and try different tactics for as long as you want.

Due to the previously mentioned saving mechanics it is also possible to leave the game during a turn-event. This has proven helpful for me more than once, when I moved to attack a town but first wanted to check my other armies to see if any of them could reinforce. I then accidentally hit 'end turn' before fighting the battle, thereby continuing the siege for another turn. In these cases, a quick Alt+F4 allows you to finish your turn like you had intended to.

Note: Using the 'return to main menu' function can work too, unless you are attacked right at the start of the turn-event as this saves the game. So while Alt+f4 might take longer to load up again, it might be a safer option.

Be careful when crossing the seas (especially as non-viking factions). I managed to complete an ultimate victory on legendary victory with 1 loss. Right before achieving a long victory my fleet was caught by an enemy army and there was no way of winning. I did not lose any other battles after that, but it was too late for the achievements.

Obviously it might pay to work your way up from 'hard' difficulty, if you are not a fully-fledged (exclusively legendary) Total War player yet. After all, this is a computer game and not a real-life simulator, so it pays to know the game-mechanics. Learn what the AI does, and how it 'thinks' so you can better anticipate its moves. This will help you win battles at incredible odds.

Adapting your strategy to suit the AI's weakness is still strategy, applying real-world historical strategies against an AI that plays by different rules is just dumb (for instance raiding towns, even though the AI has a big food bonus over the player).

Note: Even if you have experience with legendary difficulty in Total War games, it might be useful to play the first two campaign on hard and very hard (to become familiar with the game's mechanics). Since this is needed in order to get all the achievements anyway, it might as well be your first two campaigns.

When I started playing Legendary myself, one of the biggest adjustments was not being able to pause during battles. I tended to micro manage my battles by pausing, giving orders, and un-pausing. This is not possible on legendary, and will likely lead to higher casualties at first. Over time you'll start to plan your battles differently; in a way that requires less micro-management.

The second big change was not being able to create several save files in the campaign, just means i have to think twice before doing something. See the "Battle achievements" section for more tips on playing legendary.

I saw some forum posts from people wondering whether this can be obtained with Mide, while on others it was said to be impossible. I can confirm it is possible to obtain this achievement with Mide as well. I got it with them by annexing most Irish factions (liberating a few in the process). It is not required to liberate every Irish faction! I did not annex Ulaid, Iarmuma, and Desmuma, so I 'only' annexed 9 of them.

I think it only matters that you, as a player, don't vanquish any Irish factions, but if the computer does so it is no problem. This theory is based on a forum post from someone claiming they conquered multiple factions and only annexed the final one. Apparently this did not trigger the achievement for them.

As a final note, Scotland was completely taken over by Sudreyar and Orkney by the time I annexed the last Irish faction (so no more Scottish Gaels). This could also be one of the reasons why it did trigger for me and not for other people.

I got it during my Northymbre campaign on very hard difficulty. I tried to keep the meter in the orange middle squares but when Northleode declared war (together with its vassal) it jumped 1 square into the green. Keeping it in the middle took a lot of reloading autosaves when I got attacked between turns. I recommend
- leaning towards the English side of the two middle squares, as it is easier to declare war on a faction when it jumps into the green, than it is to make peace.
- try to declare war on small factions and subjegate them ASAP to return the meter to its original position.

This one is easy to get by regularly waging war. I think it is almost impossible NOT to get this upon playing a full campaign, especially once more technologies have been unlocked.

Note: I read elsewhere that you need to play the campaign in an earlier patch to get this achievement. I haven't tried this myself, so I can't confirm it. Once I can confirm it myself I will update with a more extensive explanation. I can now confirm reverting to the "allegiance patch" works.

To obtain the achievement you could either:
- play a complete campaign for either of the Welsh factions, or
- select 'easy' and quickly obtain this achievement through short victory.
I went for short victory with Gwined on easy difficulty. It took me 54 turns to conquer all of Wales and thereby achieve a short kingdom victory. The achievement popped at the beginning of turn 55.

To set your game to the the allegiance patch:
right click the game in your library > select properties > go to the "betas" tab > select "allegiance_patch - allegiance_patch > hit "close"
The game will need to 'update' before you can play; which might take a while.

Update:
It seems this option has been (temporarily?) disabled. I do not know if this makes it impossible to obtain this achievement.

As you start the campaign with less than 20 heroism, You need to enact the "+10 heroism" edict in the first turn. This should bring your heroism close to 20. Also defeat the rebel army during the first turn (to level up your general), which should bring your heroism at or above 20.

Circenn

conquer all Scottish regions

Dyflin

conquer all Irish regions

East Engle

conquer all English regions

Gwined

conquer all Welsh regions

Mide

conquer all Irish regions

Mierce

conquer all English regions

Northymbre

conquer all Scottish regions + conquer all English regions

Strat Clut

conquer all Welsh regions

Sudreyar

conquer all Scottish regions

West Seaxe

conquer all English regions

In order for this achievement to trigger, the player must own all the regions themselves. This also means you cannot have any vassals in that area!

Short Conquest

Control +/-50 settlements, and +/-10 provinces either directly or through vassals.
(the exact number varies between factions)

Short Fame

Reach 256 fame and own 3-5 buildings
(which buildings and how many varies per faction)

Short Kingdom

This is the most varied victory condition, but it usually requires you to control specific
provinces. Some factions have a secondary requirement for this victory (for instance Mide and Northymbre).

Long Conquest

Control +/-100 settlements, and +/-20 provinces either directly or through vassals.
(the exact number varies between factions)

Long Fame

Reach 532 fame and own 6-8 buildings
(which buildings and how many varies per faction)

Long Kingdom

This is the most varied victory condition, but it usually requires you to control specific
provinces. Some factions have a secondary requirement for this victory (for instance Mide).

Ultimate

For this achievement you must wipe out all the invading Viking fleets / armies that spawn
throughout the campaign (so also those single army fleets that spawn earlier). A number of turns
after achieving a Long victory, several large fleets spawn at once. It seems the number of fleets
depends on the difficulty of the campaign (3 fleets for legendary, 2 for very hard, and 1 for hard).

If you want to go for the 0 losses (on legendary) achievement it is a good idea to prepare your defenses early against the invading Viking armies. It is a good idea to aim your coastal settlements at defense by upgrading these to the highest level and building defense buildings.

Helpful buildings to improve city strength are:
- Garrison (increases town garrison & reduces travel distance for enemy armies)
- Forge (weapon & armour upgrade for all garrisoned units *)
- Arena (army and garrison units in the province gain extra experience & they replenish quicker)
- Granary (food producing building ensures you have continue to have a certain amount of food even if the smaller villages are taken / raided)

* Since the Forge only provides the upgrades for garrison units added after the forge was built, it is advisable to build the forge before the garrison, and before the town is fully upgraded.

I played this campaign on very hard difficulty and the city was not attacked more than 2 or 3 times. Once you have secured Dublin's surrounding settlements the only attacks will come via the sea. As everyone but the Sea Kings and Viking invaders get sea-sickness debuff when attacking from water, it should not be hard to defend against such attacks. Especially as the Viking invaders will likely not make it that far anyway (if you manage to hold the other cities).

This means you will likely get this achievement without any additional effort. I do recommend keeping a general close anyway, but I'll explain why in a tip in the long victories list of this section.

While this shouldn't come as a surprise for those who know anything about Irish history, it might be worth pointing out for those who don't. Once you conquered the whole of Ireland, you'll have to venture outside of Ireland as well in order to achieve the other achievements. When doing so, make sure you keep between 2 and 4 generals posted in several Irish cities. As unit recruitment is limited, new units require time to get to full strength, and your purse (by this point) should be well filled, I suggest at least adding a catapult regiment (or 2) to each general's army and perhaps a few infantry, archery, and cavalry units in a composition of your choice.

During the campaign, Viking invaders will continue to spawn around Ireland at various points. Even an army stationed in the centre of the Island is unlikely to reach a coast in time to block an invading army. By having between 2-4 small mobile garrison units stationed around the island, you can quickly dispatch invading armies before they take over too many minor settlements and you end up chasing them in circles.

Although catapult units might seem counter intuitive to quick response armies, their defensive capabilities are disproportionately useful despite there restricted movement-range. An army of a few strong infantry units and 2 catapult regiments can easily defend a bridge against full stack armies (as long as you make sure you don't hit your own troops). Likewise, when defending a coastal city against a fleet, catapults can virtually take out a full-stack army themselves. All that's needed is a small token-force to defend against the 1 or 2 ships that do manage to get to shore.

Annex 2 factions

See the "Culture achievements" section in this guide for information on how to
annex factions as Mide. I have also published a separate guide on how Legitimacy
works for Mide.

Conquer 100 settlements, and 20 provinces.

To get this achievement you'll need to conquer regions outside of Ireland as well.
However, if you are also trying to annex all Gaelic factions during this playthrough,
it is best to wait with your conquest outside of Ireland until you have obtained this achievement. Every settlement the AI takes from you is -1 legitimacy, and only
settlements in Ireland provide +1 legitimacy when conquered. This means if you have
settlements outside of Ireland, and they get taken by the AI, you're wasting legitimacy. (more information on legitimacy is in the "Culture achievements" section).

Annex 2 factions

Luckily the long version does not require any additional annexations! See the
"Culture achievements" section in this guide for information on how to annex
factions as Mide.

As far as I'm aware it is not necessary to complete both of these in the same run. Nevertheless, it is possible to do it. Northymbre is the only faction with 2 'capture country' achievements.

This victory condition requires you to capture 1 area in Wales, which means it is the only one you cannot achieve by focusing only on England and Scotland (I have no idea why they felt the need to this).
However, it is still possible to obtain this victory once you've completed the ultimate victory. So there is no need to rush this Welsh settlement if (like in my campaign) the town is held by an ally or vassal.

Gwined

Aberffro

Powis

Mathrafal

Seisilwig

Aberteifi or Dinefwr

Gwent

Cair Gwent