The Behind the Throne Add-on for Old World has 8 achievements.
Win on New Difficulty
Complete opulence project with an extravagant leader (Behind the Throne)
Lose a bet, win the game without that city (Behind the Throne)
Declare war impulsively (Behind the Throne)
Welcome the Special Ambassador (Behind the Throne)
Remove a Grand Vizier with a scheming mission (Behind the Throne)
Win at the gamble mission (Behind the Throne)
Complete a Grand Vizier's reform program (Behind the Throne)