In 1291, de Severy was present at the
Siege of Acre in his capacity as Marshal, serving under Grand Master
Guillaume de Beaujeu. On 18 May 1291, the
Mamluks launched a general assault and breached the city's walls. Guillaume de Beaujeu was mortally wounded during the fighting and died shortly afterward, leaving de Severy as the senior Templar commander leading the defense within the city. On the night of 25–26 May, de Severy dispatched
Thibaud Gaudin by sea to
Sidon carrying the treasury of the Order, along with non-combatants who could be evacuated. He then continued to hold the Templar fortress, the last Crusader stronghold still resisting, to protect the civilians sheltering within while they awaited further evacuation. Sultan
Al-Ashraf Khalil offered terms: if the Templars surrendered the fortress, the lives of those sheltering within would be spared. De Severy accepted. However, when Mamluk soldiers entered the fortress and began attacking the civilians, the Templars expelled them and barred the gates. The Sultan subsequently sent word that his men had acted without orders and invited de Severy to his camp to personally renew the terms. On 28 May, de Severy and his companions emerged to negotiate but were promptly bound and executed. Following the executions, the Sultan's forces undermined the fortress; the building collapsed during the final storming, killing the remaining defenders and the Mamluk attackers inside. Following de Severy's death,
Thibaud Gaudin was elected Grand Master of the Order in Cyprus. ==See also==