Full list of all 138 Crusader Kings III achievements. It takes around 200 hours to unlock all of the achievements in the base game on Windows.
The base game contains 56 achievements, and there are 6 DLC packs containing 82 achievements.
Marry another character
Complete an entire Lifestyle (all three trees)
Complete an entire Dynasty Legacy
Create a Cadet Branch of your Dynasty
Have the maximum amount of dread
Suffer from a Mental Break
Use the Claim Throne scheme successfully
Have ten living children
As Álmos Árpád, form Hungary and convert to Christianity
As Nuno II Vimaranes, form Portugal
Have one hundred living dynasty members
Have your dynasty reach the highest possible Level of Splendor
Play until 1453
Reach the highest possible Stress level
Starting as an Iberian Christian, convert all of Iberia to Christianity
As a Hindu ruler, hold all seven Hindu Holy Sites at the same time
As a French Catholic, hold the Kingdom of Thessalonika without being vassalised to Byzantium
Reach the highest possible Prestige Level
Reach the highest possible Piety Level
Have a child with the Inbred trait
Found a Holy Order
Have strong hooks on three direct vassals
Know ten secrets simultaneously
Have your Dynasty rule ten independent realms of at least Kingdom tier simultaneously
Restore the Roman Empire
Starting as an Irish ruler, hold the Kingdom of Ireland
Starting as a Count, lead your line to rule an Empire
Starting as Matilda di Canossa in 1066, rule Italy, have 50 Dynasty members, and found a Holy Order
Starting as an Iberian Muslim, control Iberia and take the Avenge the Battle of Tours decision
Starting as Robert the Fox in 1066, rule Sicily, hold a Greek Kingdom, and convert it to Catholicism
Starting as any of the Jimena siblings in 1066, become Emperor of Spain
Starting as any child of Ragnarr Lothbrok, conquer all of the British Isles
Starting as Eudes Capet in 867, lead your Dynasty to rule the Kingdom of France
Starting as William in 1066, win the Invasion, become English, and have only English vassals
Starting as Vratislav Přemyslid in 1066, lead your Dynasty to rule Bohemia and the Holy Roman Empire
As Haesteinn of Nantes in 867, hold any Kingdom tier title
Starting as Rurik the Troublemaker in 867, lead your dynasty to rule the Empire of Russia
Have a strong hook on your Head of Faith
Have three or more virtuous traits
Have a lover save you from a murder attempt
Use a hook to modify a feudal contract
Defeat a faction in a war
Fully upgrade a duchy capital building anywhere in your personal domain
Create a Faith
Murder your lover's spouse
Inherit a title from someone you murdered
Murder your spouse
Take part in a successful Great Holy War, on either side
Go to war with one of your siblings over a Claim
As any one character, successfully seduce ten people
While holding any empire title, be naked
Have only two distinct parents, grandparents, and great grandparents
Starting as a Karling, be the only independent Karling to hold a landed title
Increase your Rank
Have your culture unlock all innovations, excluding regional and culture-specific innovations
Starting as Daurama Daura, have your line reform an African faith, and convert all of Africa to it
As a Norse-Asatru ruler, have your capital on any island in the Indian Ocean
As an Asatru, hold all of the original Thessalonika, and any empire title other than Byzantium
As an unreformed tribal, form the North Sea Empire
As a North Germanic Asatru, control all islands in the Atlantic and the Mediterranean, whilst keeping your realm size below a certain threshold
As a Norse tribal, control the entirety of Sicily
Form a coven as a female Asatru witch
As any one dynasty, commission a hundred rune stones
As a Christian North Germanic, participate in the very first crusade from the start
As a North Germanic or Asatru ruler, convert to Islam & convert all of Russia
As a dwarf, win a Varangian Adventurer war anywhere outside of Europe
Fund an Inspired character's Project, and recieve the end result
Create a Hybrid Culture
Create a Divergent Culture
Have an artifact in every slot in the Inventory and Court
Reach the maximum amount of Court Grandeur
Personally know 10 languages
Sponsor 30 successful inspirations in one game
Obtain a mythological rarity artifact from an Adventurer Inspiration
Rule a realm containing at least 10 cultures with 95% or more acceptance of your culture
Be at least 6 levels above your expected Court Grandeur
As a member of the Pugyel Dynasty, re-create the Empire of Tibet
As the Seljuk Count in Samosata, form Rum and create a Hybrid Culture between Oghuz and Greek
Starting as the Duke of Ghur in 867 or 1066, conquer the borders of the historical Ghurid Empire
As the Piasts in 867, rule a Feudal Poland and own a Famed+ regalia, crown, weapon, and armor
Have every Royal Court speak your Court Language
Starting and staying as a Jewish ruler in East Africa, rule a Kingdom and diverge your culture
Appoint a character with a completed Adventure inspiration as your Antiquarian
Loot an artifact you do not have a claim on and pass it down to your heir
With the County of Fika as your primary title, diverge your culture and spread it to 30 Counties
As a vassal king to an emperor, have a higher court grandeur than they do
Sleep with your best friend while having the "Ritualized Friendship" cultural tradition
Embrace the Basque paganism faith during the Iberian struggle
Use a friendship hook on a different-faith ruler involved in the Iberian struggle
Bet a title on a strategy game match against another ruler
As an Iberian culture character, control all of the Caucasian Iberia region
Convert all of Iberia to the Mozarabic faith
End the Iberian struggle through means of force
End the Iberian struggle by setting your differences aside
End the Iberian struggle through compromise
Start as an uninvolved character, become involved and end the Iberian struggle
Create and rule the kingdom of Valencia as an heir to El Cid
Visit ten Kingdom Tier Vassals on a Grand Tour
As a Regent, sucessfully coup your liege to take their Realm without War or Schemes
As an Emperor, go on an Intimidation Tour visiting all of your Powerful Vassals
Successfully host a Murder Feast or Bloody Wedding
Finish both tracks of the Traveler Trait
Finish any track in the Hastiluder Trait
Finish all tracks in the Hastiluder Trait
Orchestrate a Grand Wedding where the Spouses become Soulmates
Have one of your Lowborn Knights win a Grand Tournament, then land them
Succeed with the Murder Intent while on a Hunt
Capture a large wild animal while on a Hunt
Finish the Falconer track in the Hunter Trait
With one Character, go on Pilgrimages to all of your Holy Sites
Participate in a Joust with a maxed out Horse track for the Hastiluder Trait
Pass through every Terrain, including navalm whilst on the same Travel
Succeed at a Legendary Hunt
Win every Contest at a Grand Tournament with at least three Contests
Have a max rank Acclaimed Knight with the Warrior of the Faith Trait
Starting as the Habsburgs, rule the Archduchy of Austria, plan 5+ Grand Weddings and don't wage War
Have a capital Barony with 60+ income, a stationed 500+ Heavy Cavalry Regiment and a mine
As a character of a faith with the Fadaeyeen Doctrine, dispose of a Lowborn, a King and an Emperor
Fill Five Tax Collector slots with excellent Aptitude characters
Take the Iranian Resurgence ending in the Iranian Intermezzo Struggle
Take the Strenghten the Caliphate ending in the Iranian Intermezzo Struggle
As a character of Iranian Heritage, hold the Empire of Persia, Kingdom of Thessalonika, and Kingdom of Hellas
Loot four Illustrious-Tier Vizier Extravagance Modifiers from your Vizier
Have 10 vassals of a different faith than yours under Jizya Law
Starting as a member of the Umayyad Dynasty, hold the Empire of Arabia and the Sunni Caliphate
Take the 'Found a New Caliphate' foundation as part of the Abbassid Humiliation ending in the Iranian Intermezzo Struggle
Take the 'Dominate the Caliph' foundation as part of the Abbasid Humiliation ending in the Iranian Intermezzo Struggle
Contract, and recover from, the Bubonic Plague
Reach the maximum level of Legitimacy
Travel to a safe holding while your Capital is infected by a Epidemic
As a Scottish character, complete a Legend claiming your descent from Ancient Egypt
Manage to make your Legend Protagonist a Saint
Successfully claim your Liege's title while having a higher Legitimacy Level than them
Have an infected Barony at the maximum Epidemic Resistance
Complete a Legend
Host a Funeral for your Legend Protagonist
As a Count, complete a Mythical Legend
Complete your ancestor's Legend after their death