sentences:  In 305, he succeeded his father Tuoba Yituo, as the chieftain of the central Tuoba territory, under his uncle Tuoba Yilu, then the Duke of Dai.In 316, Tuoba Yilu, then carrying the title the Prince of Dai, was killed by his son Tuoba Liuxiu (拓跋六修), Tuoba Pugen hears of the news and attacked Tuoba Liuxiu with an armed force and killing him, and succeeded Tuoba Yilu as the Prince of Dai.In light of Tuoba Yilu's death, however, much of the ethnically Han and Wuhuan force that Tuoba Yilu commanded left Dai and gave their allegiance to the Jin official Liu Kun (劉琨).