Here is the full list of all 14 Small Kingdoms Prologue achievements.
Conquer the campaign world
Fight an army vs army battle
Fight a siege battle
Fight a ship vs ship battle
Open the Options window
Capture an enemy city
Raze an enemy city
Loot an enemy city
Open the Help window
Play a game as the Kingdom of Oleria
Play a game as the Kingdom of Adagra
Play a game as the Kingdom of Karaman
Play a campaign as the Kingdom of Nogara
Start the game