In 1306, the King of Champa Che Man offered Vietnam two Cham prefectures, O and Ly, in exchange for marriage with a Vietnamese princess named Huyen Tran.[1] The Vietnamese King Tran Anh Tong accepted this offer.[1] He took and renamed O and Ly prefectures to Thuan prefecture and Hóa prefecture, respectively, with both of them often referred to as Thuan Hoa region.[1][2]