Khwarezmian control
Jerusalem fell again in 1244 to the Khawarezmi Turks, who had been displaced by the advance of the Mongols. As the Khwarezmians moved west, they allied with the Egyptians, under the Egyptian Ayyubid Sultan al-Malik al-Salih. He recruited his horsemen from the Khwarezmians, and directed the remains of the Khwarezmian Empire into Palestine and Syria, where he wanted to organize a strong defense against the Mongols. In keeping with his goal, the main effect of the Khwarezmians was to slaughter the local population, especially in Jerusalem. They invaded the city on July 11, 1244, and the city's citadel, the Tower of David, surrendered on August 23.[11] The Khwarezmians then ruthlessly decimated the population, leaving only 2,000 people, Christians and Muslims, still living in the city.[12] This attack triggered the Europeans to respond with the Seventh Crusade, although the new forces of King Louis never even achieved success in Egypt, let alone advancing as far as Palestine.