Li Shimin's grandmother Duchess Dugu was a sister of Empress Dugu, both of whom were daughters of Dugu Xin (獨孤信), a major general during Sui's predecessor dynasty Northern Zhou.
Li Shimin's grandmother Duchess Dugu was a sister of Empress Dugu, both of whom were daughters of Dugu Xin (獨孤信). Dugu Xin (獨孤信) was a major general during Sui's predecessor dynasty Northern Zhou.