Ibelin was a crusader castle in the Latin Kingdom of Jerusalem. It was the fief of the noble house of Ibelin, which later achieved great prominence in the kingdom. Ibelin was built in 1141 by King Fulk of Jerusalem to guard the kingdom's southern border, though its importance declined as the border moved south. It remained the centre of the Lordship of Ibelin, until the collapse of the Kingdom of Jerusalem in 1187. The castle was captured by Saladin in 1187 after the crusader defeat at Hattin, and was destroyed.