They defeated a force sent against them by the Songzhou governor Han Wei. According to the Chinese annals, Taizong responded by commissioning the general Hou Junji to command an army, assisted by the generals Zhishi Sili (執失思力), Niu Jinda (牛進達) and Liu Jian (劉簡). Led by Niu, the Tang army inflicted heavy casualties on the Tibetans in a surprise night-time attack. Alarmed, Songtsen Gampo withdrew, sent emissaries and tributes to Chang'an to apologize and to again request marriage. Emperor Taizong agreed this time.