by Subutai and Jebe (the Arrow). Abandoned by the remnants of his panic-stricken troops, Muhammad seeks shelter on a small island near Astara. There he dies of pleurisy some weeks later. He is succeeded by his son Jalal al-Din Mangburni, who is forced to flee to India after the Mongol invasion (see 1219). Autumn – Genghis Khan moves against the wealthy city of Urgench. He is joined by his eldest son Jochi, now conqueror of half a dozen lesser towns who attacks it from the north. Despite a stout defense, the city is taken after a 5-months siege. The Mongols have to fight for Urgench street by street, razing many houses. Jochi is given the right to loot the city for himself, but prefers to negotiate with the locals to avoid property damage. This is refused by Genghis, who removes Jochi from command and appoints Ögedei instead. November – Genghis Khan dispatches his youngest son Tolui, at the head of an army (around 50,000 men), into the Khwarazmian province of Khorasan. His forces also include 300 catapults, 700 mangonels to discharge pots filled with naphtha, 4,000 storming-ladders, and 2,500 sacks of earth for filling up moats. Among the first cities to fall is Termez (captured after a two-day siege) and later Balkh. England Spring – King Henry III makes large alterations to the Tower of London including new curtain walls, an improved water-filled ditch, and a water gate, so that he can enter the castle directly from the Thames. May 17 – The 12-year-old Henry III is crowned at Westminster Abbey. He is reminded of his duties as king to maintain peace, defend the rights of the English crown, and the barons swear an oath of fealty. Llywelyn the Great, Welsh prince of Gwynedd, begins raiding Pembrokeshire to retake land that he accuses William Marshal (the Younger) of stealing. This also includes Wiston Castle. Europe April 26 – King Frederick II gives rights of independence to the German bishops (the Confoederatio cum principibus ecclesiasticis) in an attempt to secure the election of his 9-year-old son, Henry VII as King of Germany. August 8 – Battle of Lihula: Estonian forces encircle the Lihula stronghold, occupied by an invading Swedish Crusader army. The Swedish troops along with Charles the Deaf try to make their way out, but they are killed. November 22 – Frederick II is crowned Holy Roman Emperor at Rome