Here is the full list of all 29 History - there are Great Battles Medieval achievements worth 1,000 gamerscore.
Win a ranked match
Get a unit into each corner of the screen
Recruit first troop
Complete the Tutorial
Complete a flanking maneuver
Win a battle with one of each unit type
Win first battle as English
Win first battle as French
Kill 500 troops
Kill 1000 troops
Win a battle with only mounted units
Win a battle with only knight units
Win a battle with only infantry units
Win a battle with only ranged units
Get a knight unit to level 10
Get a mounted unit to level 10
Get an infantry unit to level 10
Get a ranged unit to level 10
Win a battle without losing a unit
Recruit max number of units
Kill 2000 troops
Recruit 10 units
Win the English campaign
Win the French campaign
Win a Short Tug of War
Win a Long Tug of War
Win a Sandbox Match
Kill 5000 troops
Kill 10000 troops