Mongke Khan dies besieging Diaoyu in Sichuan

August 11, 1259

The fourth Great Khan died of dysentery, or perhaps a Song crossbow bolt, during the long siege of Diaoyu fortress. His death halted Mongol offensives on four fronts and set in motion the succession war between his brothers Kublai and Ariq Boke. The fortress of Diaoyu, perched on a cliff above the Jialing River, had defied Mongol siege for six years and altered the course of world history.