Nguyễn Quang Toản to flee to Thăng Long. In 1802, Ánh besieged Thăng Long. The then 20-year-old Nguyễn Quang Toản escaped, but then was captured and executed, ending the dynasty after 24 years, and the Nguyễn, the last imperial dynasty of Vietnam, took over the country in 1802. The Nguyễn lords eventually defeated the Tây Sơn dynasty, took complete control of Vietnam, and established the imperial Nguyễn dynasty in 1802. The Nguyễn used crushing by elephant to execute the defeated Tây Sơn leader Bùi Thị Xuân. The heart and liver from her body were consumed by soldiers of the Nguyễn. See also Tây Sơn military tactics and organization Ten Great Campaigns Notes Citations Bibliography Former monarchies of Asia