In 1285, the Mongol army invaded Vietnam for the second time. Upon hearing the news, the great army led by Tran Hung Dao had to confront the powerful enemy and had to retreat to Van Kiep. Tran Quoc Tang immediately brought his troops from An Sinh (Dong Trieu) along with the Hai Dong, Van Tra, and Ba Diem forces, to request leading the vanguard in fighting against the enemy. After the successful resistance, Tran Quoc Tang, a valiant general with significant contributions, was praised by the king and granted land to establish his own settlement in Tinh Bang (Quang Ninh).