The battle was initiated by the Mongols, who sensed opportunity in the political turmoil caused by their successful 1283 invasion of the Pagan Empire in the Battle of Bhamo. After Bhamo, the Mongol army penetrated the Irrawaddy River valley and established garrisons there. The political turmoil of these events tempted Kublai Khan's grandson Esen-Temür who was stationed in Yunnan, to action. Temür led a large army down the Irrawaddy river valley and captured the capital city Pagan, also sending military parties across the country to ensure submission.