Larian Studios Forums Baldur's Gate III Baldur's Gate III - Story & Character Discussion Oath of the crown palladin breaks oath when Aylin is freed.

Checking the wiki:

"Killing or freeing Aylin if previously agreed to deliver her to Z'rell"

And

"Not letting Balthazar deliver her to Ketheric Thorm if promised him to help"

Will break Crown Paladin's Oath.

This aligns with the tenets of Crown Paladins:

"Loyalty. Your word is your bond; without loyalty, oaths and laws are meaningless."

If you tell someone you will do something, then don't do it, your Oath is broken.