King Trần Nhân Tông was a prominent Vietnamese monarch who ruled from 1278 to 1293 during the Trần Dynasty. He is best known for his leadership during the Mongol invasions of Vietnam, successfully defending the country against formidable forces in battles such as the Battle of Bạch Đằng River. After his reign, Trần Nhân Tông became a Buddhist monk and founded the Trúc Lâm Zen School, promoting the integration of Buddhism with Vietnamese culture. His legacy is celebrated for both his military prowess and his contributions to the spiritual and cultural development of Vietnam.