Editing Kingdom of Jerusalem (section)

=== Crusade of Louis IX ===
The Ayyubids were still divided between Ayyub in Egypt, Isma'il in Damascus, and Dawud in Kerak. Isma'il, Dawud, and [[al-Mansur Ibrahim]] of Homs went to war with Ayyub, who hired the [[Khwarazmian dynasty|Khwarazmians]] to fight for him. The Khwarazmians were nomadic Turks from central Asia, who had recently been displaced by the [[Mongol Empire|Mongols]] further to the east and were now residing in Mesopotamia. With Ayyub's support, they [[Siege of Jerusalem (1244)|sacked Jerusalem]] in the summer of 1244, leaving it in ruins and useless to both Christians and Muslims. In October, the Khwarazmians, along with the Egyptian army under the command of [[Baibars]], were met by the Frankish army, led by Philip of Montfort, Walter of Brienne, and the masters of the Templars, Hospitallers, and Teutonic Knights, along with al-Mansur and Dawud. On October 17 the Egyptian-Khwarazmian army destroyed the Frankish-Syrian coalition, and Walter of Brienne was taken captive and later executed. By 1247, Ayyub had reoccupied most of the territory that had been conceded in 1239, and had also gained control of Damascus.{{Sfn|Tyerman|2006|pp=770–771}}

[[Seventh Crusade|A new crusade]] was discussed at the [[First Council of Lyon|Council of Lyon]] in 1245 by [[Pope Innocent IV]]. The council deposed Frederick II, so no help could be expected from the empire, but King [[Louis IX of France]] had already vowed to go on crusade. Louis arrived in Cyprus in 1248, where he gathered an army of his own men, including his brothers [[Robert of Artois]], [[Charles of Anjou]], and [[Alphonse of Poitiers]], and those of Cyprus and Jerusalem, led by the Ibelin family [[John of Ibelin (jurist)|John of Jaffa]], [[Guy of Ibelin, constable of Cyprus|Guy of Ibelin]], and [[Balian of Beirut]]. Once again the target was Egypt. Damietta was captured without resistance when the Crusaders landed in June 1249, but the crusade halted there until November, by which time the Egyptian sultan Ayyub had died and had been succeeded by his son [[Al-Muazzam Turanshah|Turanshah]]. In February, the Crusaders were defeated at the [[Battle of Mansurah (1250)|Battle of al-Mansurah]], where Robert of Artois was killed. The crusaders were unable to cross the Nile, and, suffering from disease and lack of supplies, retreated towards Damietta in April. They were defeated along the way at the [[Battle of Fariskur (1250)|Battle of Fariskur]], with Louis being taken captive by Turanshah. During Louis' captivity, Turanshah was overthrown by his Mamluk soldiers, led by the general [[Aybak]], who then released Louis in May in return for Damietta and a large ransom. For the next four years Louis resided in Acre, and helped refortify that city along with Caesarea, Jaffa, and Sidon. He also made truces with the Ayyubids in Syria, and sent embassies to negotiate with the Mongols, who were beginning to threaten the Muslim world, before returning home in 1254. He left behind a large garrison of French soldiers in Acre, under the command of [[Geoffrey of Sergines]].{{Sfn|Tyerman|2006|pp=784–803}}

In the midst of these events, Alice of Champagne had died in 1246 and had been replaced as regent by her son King [[Henry I of Cyprus]], for whom John of Jaffa served as ''bailli'' in Acre. During Louis IX's stay in Acre, Henry I died in 1253, and was succeeded in Cyprus by his infant son [[Hugh II of Cyprus|Hugh II]]. Hugh was technically regent of Jerusalem as well, both for Conrad and for Conrad's son [[Conradin]] after Conrad died in 1254. Both Cyprus and Jerusalem were governed by Hugh's mother [[Plaisance of Antioch]], but John remained ''bailli'' for Hugh in Acre. John made peace with Damascus and attempted to regain Ascalon; the Egyptians, now ruled by the [[Mamluk Sultanate (Cairo)|Mamluk sultanate]], besieged Jaffa in 1256 in response. John defeated them, and afterwards gave up the bailliage to his cousin [[John of Arsuf]].{{Sfn|Edbury|1991|pp=81–85}}