While in Palermo, Yolanda, Queen of Jerusalem, gives birth to Conrad, son of Frederick II of Hohenstaufen. The delivery is hard on the sixteen year-old and she dies in a few hours.
The marriage between Frederick II and Yolanda was of course political: she had nothing to say in the matter, but Frederick had told Pope Honorius III that he would only embark on the Fifth Crusade if he could be the legitimate king of Jerusalem. That was only possible if he married the much younger Yolanda, which he did.
With her death, Jerusalem was now ruled by Frederick alone, a man with no blood ties to the first families that had captured Jerusalem and the Holy Lands. In effect, Jerusalem is now ruled by foreigners again.