Here is the full list of all 100 Knights of Honor II: Sovereign achievements.
Become a vassal.
Establish a colony.
Provoke war between two kingdoms with a Spy action.
Fail an Emperor of the World claim.
Organize a prison revolt.
Make all Upgrades of a Trade Port.
Reach 100 piety/faith/tradition income.
Make all Upgrades of a Royal Palace.
Instigate a crusade.
Win a naval battle.
Have 6 marshals at the same time in your royal court.
Have your army killed by the arrows of a nearby town or castle.
Claim independence.
Top all 3 Conquest-related rankings at the same time.
Reach the maximum level with all of your court knights.
Reach 400 commerce.
Have the opinions of all society classes reach maximum values at the same time.
Reach 100 books income.
Start a war by sending or refusing a territorial claim.
Sign 50 trade agreements.
Participate in a battle, in which 3 other kingdoms are involved.
Initiate break siege with your king from within a town.
Support another player in a battle.
Win a Grand Campaign in under 5 in-game hours.
Top all 3 Wealth-related rankings at the same time.
Lead an alliance of at least 3 kingdoms.
Win the game.
Win a Grand Campaign after starting with a single-province-sized kingdom.
Win a game by developing all advantages.
Make all Upgrades of a University or a Madrasah.
Make all Upgrades of a Cathedral or a Grand Mosque.
Reach 500 gold income from trade.
Become a Great power.
Reach 150 food production.
Use all building slots in a town.
Execute or assassinate a king.
Produce Maps.
Fully develop an advantage.
Reach 100 levies income.
Have 3 or more rebellions simultaneously.
Destroy a kingdom.
Top a ranking.
Hire knights in each slot of your royal court.
Execute 10 prisoners in a single game.
Have your king lead a crusade.
Lose a level 15 character.
Reach 200 gold income.
Overtake a foreign province.
Have one of your towns become a trade center.
Defeat a rebellion by force.
Reach the maximum level with one of your knights.
Pillage 15 settlements in a single game.
Start a multiplayer game.
Help your knight escape from a dungeon by using a Spy.
Have a non-Marshal (nor Shaman) knight lead an army.
Declare war on a kingdom with which you’ve signed a non-aggression pact.
Defeat a crusader army marching against you.
Destroy the kingdom of another player.
Pick a new kingdom in a multiplayer game after your first one was destroyed.
Assassinate a knight of another player with a Spy.
Have an army reach 7,000 manpower.
Complete a Scholar’s journey.
Top all 3 Culture-related rankings at the same time.
Top all 3 Society-related rankings at the same time.
Top all 3 Politics-related rankings at the same time.
Have a cleric of yours become the Pope.
Have the Ecumenical patriarch as a knight in your court.
Establish a caliphate.
Claim autocephaly.
Destroy the Papacy.
Have at least 3 pagan beliefs promoted at the same time.
Win a Peasant’s Rush game by reaching the target kingdom’s size.
Win a Greedy Kings game by collecting the target amount of gold.
Win Destroy kingdom by destroying the target kingdom.
Win a “First blood” game by destroying an opponent.
Win a game by becoming the Emperor of the World.
Top all rankings at the same time.
Own 100 provinces.
Hold Constantinople, Mecca and Rome at the same time.
Change your kingdom's religion twice in a single game.
Refuse peace offer when you have only one town, that is being besieged.
Declare independence while playing with Scotland.
Adopt Heroes and Battles beliefs.
Send gold to another kingdom while playing as Leinster.
Declare war on Salamanca.
Reach the west end of the known world.
Own 5 trade centers at the same time.
Gain 20 provinces via diplomacy.
Conquer 250 provinces by force.
Convert 100 provinces to your kingdom’s religion.
Pillage 100 settlements.
Actively end disorder in 200 provinces.
Win 1000 battles.
Destroy 50 kingdoms.
Using a diplomat, improve your relations with other kingdoms 1,000 times.
Vassalize 50 kingdoms.
Bribe 100 knights.
Import 20 goods.
Adopt Oceans and Raids beliefs.
Win a War for Goods game by producing the target amount of goods.