In 608, Pei persuaded the Tiele to attack Tuyuhun. Tuyuhun's khan Murong Fuyun initially sought aid from Sui, but when Emperor Yang sent his cousin Yang Xiong (楊雄) the Prince of Ande and Yuwen Shu the Duke of Xu toward Tuyuhun, Murong Fuyun distrusted them and fled. Sui forces then attacked him, greatly defeating him and forcing him to flee further, seizing Tuyuhun territory and putting it under Sui control. Later that year, when Emperor Yang was set to offer sacrifices to the spirits of Mount Heng, Pei persuaded emissaries from 27 Xiyu states, headed by Qu Boya (麴伯雅) the King of Gaochang and Ashina Tutun (阿史那吐屯), the Western Tujue general in charge of Yiwu (伊吾, in modern Hami Prefecture, Xinjiang), to pay homage to him and to assist in offering sacrifices. Emperor Yang was greatly pleased by this and greatly awarded both Pei and all of the Xiyu emissaries. Around the same time, Emperor Yang made Pei Ju, along with Yu Shiji, Niu Hong, Su Wei, Yuwen Shu, Zhang Jin (張瑾), and Pei Yun (裴蘊) in charge of selecting and promoting officials, and they were known as the seven nobles of officialdom. However, it was said that the actual selective powers were in Yu's hands, and that Yu became exceedingly corrupt, making recommendations based on the amount of bribes that he received. Pei Ju, however, was known and praised for not accepting bribes.