The 1244 Siege of Jerusalem took place after the Sixth Crusade, when the Khwarezm conquered the city on July 15, 1244. As context, Frederick II, Holy Roman Emperor led the Sixth Crusade to the Holy Land in 1228, and claimed the kingship of Jerusalem by right of his wife, Queen Yolande of Jerusalem, who had inherited the title of 'Queen of Jerusalem' from her mother, Maria of Montferrat, the wife of John of Brienne.