Meanwhile, Liang Shidu, protected by Eastern Göktürk aid, was holding up against Tang attacks, and Tang itself was continually harassed by Eastern Göktürk raids. After Li Shimin ambushed and killed Li Jiancheng and another brother, Li Yuanji the Prince of Qi in 626 and effectively forced Emperor Gaozu to yield the throne to him (as Emperor Taizong), however, Tang began to turn the situation around. By 628, with Eastern Göktürk in internal turmoil due to disagreements between the Jiali Khan Ashina Duobi (Ashina Duojishi's younger brother) and the subordinate Tuli Khan, Ashina Shibobi (阿史那什鉢苾, Ashina Duojishi's son), it was no longer able to protect Liang Shidu, and under Tang siege, Liang Shidu's cousin Liang Luoren (梁洛仁) killed Liang Shidu and surrendered. China was now under the rule of Emperor Taizong.