With the full support of Pope Innocent IV during the First Council of Lyon, King Louis IX of France accompanied by his brothers Charles d'Anjou and Robert d'Artois launched the Seventh Crusade against Egypt. The aims of the crusade were to defeat Egypt, destroy the Ayyubid dynasty in Egypt and Syria and recover Jerusalem which the Muslims recaptured in 1244. The ships entered the Egyptian waters and the troops of the Seventh Crusade disembarked at Damietta in June 1249. Louis IX sent a letter to as-Salih Ayyub. Emir Fakhr ad-Din Yussuf the commander of the Ayyubid garrison in Damiette retreated to the camp of the Sultan in Ashmum-Tanah causing a great panic among the inhabitants of Damietta who fled the town leaving the bridge that connected the west bank of the Nile with Damiette intact.