Conrad of Montferrat was a northern Italian nobleman and one of the major participants in the Third Crusade. In 1189, he joined Guy of Lusignan at the siege of Akko, but a year later he sought to displace Guy as king of Jerusalem. To establish a claim to the crown, he married Isabella, daughter of Amalric I. In 1192, Conrad was acknowledged as king, but a few days later he was assassinated, and the royal title passed to the two later husbands of his widow.
Who killed him?
Source: Free Dictionary Encyclopedia.