Here is the full list of all 19 Fit For a King achievements.
Conquer the known world.
Meet your rival at the summit.
Outspend your rival at the summit.
Make your rival cry.
Marry an inanimate object.
Fill your jail with prisoners.
Fill your chamber with spouses.
Ride a horse.
Get assassinated.
Gain 5xp.
Ordain the bear.
Get a suit of gold for a monkey.
Play an anachronistic song.
Marry a princess.
Meet the leader of a distant land.
Get a suit of gold.
Have a swashbuckling adventure.
Get an evaluation of your rulership.
Reform the church.