 After the army returned to Tang territory, however, Xue was charged with killing those who had already surrendered and seizing the spoils of war and arrested for a time, but was eventually released after Emperor Gaozong ruled that the achievements outweighed the crimes.In 666, Yeon Gaesomun died, and infighting developed between Yeon's oldest son Yeon Namsaeng, who succeeded Yeon Gaesomun as "Dae Mangniji", and two younger sons Yeon Namgeon and Yeon Namsan, over suspicions that they had for each other.Eventually, Yeon Namgeon, while Yeon Namsaeng was away from the capital Pyongyang, claimed the "Dae Mangniji" title himself.