Gao Pian
The Tang launched a counterattack in September 864 under Gao Pian, an experienced general who had fought the Türks and the Tanguts in the north. In winter 865–866, Gao Pian recaptured Songping and northern Vietnam, and expelled Nanzhao from the region. Gao punished local people who had allied with Nanzhao, executed Chu Đạo Cổ and 30,000 local rebels. In 868 he renamed the region to "The Peaceful Sea Army" (Jinghai guan). He rebuilt the citadel Sin Songping, named it Đại La, repaired 5,000 meters of damaged city wall and reconstructed 400,000 bays for its residents. He was well respected even by the Vietnamese.