Here is the full list of all 80 Mount & Blade: Warband achievements. It takes around 150-200 hours to unlock all of the achievements on Windows.
Assist your faction in conquering Calradia.
Get a character to elope.
Steal 3 cattle from a single village.
You have completed the following achievements: Mace in yer Face!, Spoil the Charge, Agile Warrior, and This is our land.
(MP) Kill 50 cavalry while on foot, the enemy must be killed while mounted.
You have completed the following achievements: Abudant Feast, Mace in yer Face!, Sarranidian Nights, and Art of War/Melee Master.
(MP) Kill 25 foes with a blunt weapon.
You have completed the following achievements: Trick Shot, Khaaan!, Agile Warrior, and Harassing Horseman.
(MP) Kill 100 people with mounted projectiles.
You have completed the following achievements: Might makes Right, The Huscarl, Melee Master/Dexterous Dastard, and Holy Diver/Elite Warrior.
(MP) Kill 50 foes with throwing axes.
(MP) Kill 25 people with throwing weapons.
Be chosen as marshall.
Have a 7 in one of the following skills or a 5 in two; Tracking, Path-finding, or Spotting.
Get the engineering skill up to 5.
(MP) Perform 25 lance kills while mounted.
(MP) Win a round of team deathmatch mode.
You have completed the following achievements: Might Makes Right, Choppy Chop Chop, Glorious Mother Faction, and Old school Sniper.
(MP) In any multiplayer mode have more kills than deaths.
(MP) Win a round of deathmatch mode.
You have completed the following achievements: Melee Master, Knights of the Round, Every breath you take, I dub thee/Good Samaritan.
(MP) Slay 50 foes with slashing weapons.
(MP) Win in Conquest mode.
Rule all of Calradia!
As a female character, become queen of all Calradia.
Get either two agility related skills to 5 or one to 7.
Land a shot with a difficulty of 5 while using a throwing weapon.
Kill 10 enemies with a throwing weapon's secondary function.
Make one of your melee weapon skills 250.
Get either two strength related skills to 5 or one to 7.
As a female character, Capture and sell three NPC lords.
As a female character, give a companion character a great sword.
(MP) Win one round in battle mode.
(MP) Your team successfully defended a castle in siege battle mode.
Land a shot with a difficulty of 10 while using a bow and arrow.
Make one of your ranged weapon skills 250.
As a female character, help a female claimant reclaim her throne.
Put a pretender on their rightful throne.
Get Married.
Pick a fight with a lord by insulting him or by challenging him to a duel.
As a female character get into a duel with male lord by insulting him.
Have two of the following skills at a 5; Looting, Inventory Management, Trade, or Prisoner Management.
Kill 75 enemies with throwing weapons.
Amass a fortune of 100,000 denars.
Kill 10 parties of Mountain Bandits.
Have two of the following skills at a 5; Trainer, Tactics, Leadership, or Persuasion.
Win a battle against a lord or party who previously beat or captured you.
Get one of your healing skills to 5.
Become the owner of at least 5 fiefs.
As a ruler conquer 10 towns or castles.
Kill 75 enemies with horse archery.
Finish reading one book through the camping screen.
As a ruler have 3 vassals.
Promote one of your followers into a position of power.
Have a -50 relation with a lord, village, or faction.
Raid 3 caravans and raid 3 villages.
Successfully defend a castle.
Visit every major town in Calradia.
Camp in the Sarranid region of the map.
Learn 3 poems from tavern bards.
Defeat 10 enemy parties in the snowy regions of Calradia.
Make your own faction.
Be granted your first fief.
As a female character, make your own faction.
Sell 5 people to the ransom broker.
You and your army have killed or wounded 5,000 enemy troops.
Recruit 6 hero characters.
Harass wondering peasants on the map.
Kill or wound at least 500 enemies.
Kill 50 men as a female character.
As a female character, raise your renown to 50.
Raise your soldiers' morale from low to excellent.
Install and play one mod.
Face off against 100 enemies using custom battle mode.
Enter and win a tournament.
Eat 6 different types food concurrently.
Cleanse the town of bandits in the opening mission.
Land a shot with a difficulty of 6 while using a crossbow.
Help a lord or party win a fight.
Engage in a conversation with a hero character through the party screen.