Princess Dowager Helan (賀蘭太后, personal name unknown) (351–396), formally Empress Xianming (獻明皇后, literally "the wise and understanding empress), was, according to official history of the Xianbei-led Chinese Northern Wei dynasty, the mother of the founding emperor Emperor Daowu (Tuoba Gui).
(However, for reasons why this account may have its problems, see here—in particular, note below with regard to description of the parentage of Tuoba Gu (拓拔觚).)
Initially, she took Tuoba Gui to Helan tribe to be taken under the protection of her brother Helan Na (賀蘭訥), but later went to be under the protection of the Dugu chief Liu Kuren (劉庫仁).
In 384, after Former Qin had begun to collapse in light of its defeat at the Battle of Fei River, Liu Kuren tried to aid the Former Qin prince Fu Pi, but was assassinated by his own general Muyu Chang (慕輿常).
After Tuoba Gui redeclared the Dai state as its prince with Helan Na's support in 386 and later changed the state's name to Wei, Lady Helan was honored as princess dowager.