(17 May) The Fatimid-ruled city, Caesarea, fell to the Crusaders after a 15-day-long siege during the First Crusade. The siege began on 2 May 1101. The cruelest massacre took place in the Great Mosque where many of the citizens had taken refuge and begged for mercy. But they were butchered, men and women alike, by the Crusaders.

(17 May) Muhammad Ali Pasha or Muhammad Ali of Egypt became the Wali of Egypt in 1805.