In 1306, King Che Man used two lands Chau O and Chau Ly as an offering to marry Princess Huyen Tran (Tran dynasty), a strip of land from the south bank of Thach Han river to the north bank of Thu Bon river became Dai Viet territory. In 1307, the Tran dynasty changed the name of Chau O to Chau Thuan, and Chau Ly to Chau Hoa.

Thua Thien Hue is a large area of Chau Hoa then, whose inhabitants are mainly Cham people scattered in the O Lau river Delta, Bo river, Huong river, and Thu Bon river, including coastal lagoons. Since then the harmonious coexistence between the Cham communities and Vietnamese immigrants who reclaimed the village began to create positive changes in national construction.

Since 1307, the official migration of Vietnamese from the Thanh - Nghe plain to the new land has begun, gradually increasing the number of Vietnamese residents. In Thua Thien Hue the migration of Vietnamese took place sporadically during the fourteenth century. By the end of the XIV century, the Tran dynasty had established 7 new districts in the land of Hoa Chau: Tra Ke, Loi Bong, Sa Lenh, Tu Dung, Bo Dai, Bo Lang and The Vinh with over 40 villages, hamlets.

After Che Man's death, Princess Huyen Tran returned to Dai Viet, using this pretext that the succeeded kings brought troops to fight Chau Thuan and Chau Hoa, the Tran kings had to send troops many times to defend, setting out many policies such as assigning the custody of Chau Hoa to the courtiers or princes.  In 1372, king Tran Nghe Tong named a local official, Ho Long, as the Great Tribune of Chau Hoa, but the frontier was still unstable. In 1377, with the death of king Tran Due Tong due to a conspiracy by Chiem Thanh King Che Bong Nga, the Chiem Thanh army occupied Chau Thuan, Chau Hoa, Chau Tan Binh, and Nghe An for 12 years, until Che Bong Nga shot dead by the Dai Viet army, the Chiem Thanh army was shattered and withdraw troops from this land.

In 1391, king Tran Thuan Tong sent Le Quy Ly to patrol Chau Hoa, assess the army, and repair the stronghold, only then Chau Hoa could stabilize.

All chaotic events in Thua Thien Hue during the XIV century, have slowed down the migration to this land. The war had also made the newly formed villages miserable. The first generations of villagers were largely abandoned and the fields mostly deserted. It was not until the next century that they recovered.