Damietta, killing any Frank that strayed outside. The Franks erected dykes and dug ditches to protect the city. Advancement towards Mansurah The Nile waters receded at the end of October 1249, and Alphonse arrived with the reinforcements from France. It was time to advance on Cairo. Peter Maulcerc and the Syrian barons proposed an alternate attack on Alexandria, surprise the Egyptians and control the Mediterranean littoral of Egypt. But Louis’ other brother Robert I of Artois opposed the operation along with the king and, on 20 November 1249, the Frankish army set out from Damietta to Mansurah. A garrison was left to guard the city where the queen and the patriarch Robert of Nantes remained. Louis' timing of the move was fortuitous. As-Salih Ayyub died on 23 November 1249 after having his leg amputated in an attempt to save his life from a serious abscess. As-Salih did not trust his son al-Muazzam Turanshah and had kept him at a safe distance from Egypt in Hasankeyf. As-Salih's widow, the Armenian-born Shajar al-Durr managed to conceal the news of her husband's death, confiding only in the chief eunuch Jamal ad-Din Mohsen and the commander Fakhr ad-Din. She forged a document under his signature which appointed Turanshah as heir and Fakhr ad-Din as viceroy. Mamluk commander Faris ad-Din Aktai was sent to return Turanshah home. (Turanshah's rule would be brief. His mother married al-Malik al-Muizz Aybak, who served as Mamluk ruler of Egypt, as regent to al-Ashraf Musa and later as sultan.) When as-Salih’s death was finally revealed, the sultana and viceroy were firmly in charge. But the Franks were encouraged by the news and believed that this government would soon collapse. The route taken by the Crusaders from Damietta was crossed by numerous canals and branches of the Nile. The largest was the al-Bahr as-Saghit (Ushmum canal), which left the main river just below Mansurah and ran past Ashmun al-Rumman to Lake Manzala, isolating the island of Damietta. Fakhr ad-Din kept the bulk of his forces behind the al-Bahr as-Saghir, and sent his cavalry to harass the Franks as they crossed the canals. There was a battle near Fariskur on 7 December 1249, where the Egyptian cavalry was stopped, and the Templars, against all orders, pursued those retreating. On 14 December, Louis reached the village of Barāmūn, just ten miles to the north of their objective, and the next week encamped on