Professor Liam Kelley noted that people from Song dynasty China like Zhao Zhong and Xu Zongdao fled to Tran dynasty ruled Vietnam after the Mongol invasion of the Song and they helped the Tran fight against the Mongol invasion. The ancestors of the Tran clan originated from the modern day province of Fujian as did the Daoist cleric Xu Zongdao who recorded the Mongol invasion and referred to them as "Northern bandits". He quoted the Đại Việt Sử Ký Toàn Thư which said "When the Song [Dynasty] was lost, its people came to us. Nhật Duật took them in. There was Zhao Zhong who served as his personal guard. Therefore, among the accomplishments in defeating the Yuan [i.e., Mongols], Nhật Duật had the most." The Tran defeated the Mongol invasions of Vietnam.