Ле Лой
By 1427, captured northern prisoners also furnished the rebels with siege techniques, primitive tanks, flying horse carts, Muslim trebuchets (hui hui pao 回回砲), and possibly another artillery piece that the Chinese called a "thousand-ball thunder cannon". The Xuande Emperor of the Ming dynasty decided to end the war in Northern Vietnam. After this final victory, the Vietnamese repatriated 86,640 Ming prisoners to China and confiscated all their weapons. China would not again invade its southern neighbor for 360 years. Lê Lợi formally re-established Đại Việt as the Xuande Emperor of the Ming Empire officially recognized Lê Lợi as the king of Annam. In return, Lê Lợi sent diplomatic messages to the Ming imperial court, promising Vietnam's loyalty as a nominate tributary state of China and cooperation. The Ming imperial court accepted this arrangement, much as they accepted the vassal status of Korea under the Joseon dynasty. The case of Vietnamese monarch Lê Lợi showed that it was possible to satisfy Chinese pride while maintaining political independence.