Gilbert of Assailly (d.1183) was Grand Master of the Knights Hospitallers from 1162/3 to 1170, when he resigned or was deposed. During his time at the head of the Hospitallers, they purchased the land for Castle Belvoir, at Kawkab al-Hawa, now Beit She'an, and otherwise expanded their fortifications. Gilbert also began regulating the constitution of the order. His is principally remembered for his militant attitude to the invasion of Egypt, proposed by Amalric I of Jerusalem. The 1168 expedition turned out disastrously, and Gilbert's position became untenable.