Also written 失韋, might be a tribe of the Xianbei 鮮卑, as pronunciation is similar, or of the Khitan (Chinese: Qidan 契丹). Not very much is known of this people that appeared at the end of the north-south division and roamed the area of the west of modern Heilongjiang province and north of the River Amur. Their economy was partially nomad, with cattle breeding as main source of income, and partially agricultural. Their chieftains were called moheduo 莫賀咄 or yumofumanduo 余莫弗瞞咄. They brought tributary presents to the Tang 唐 court and disappeared in the 10th century with the foundation of the Liao empire 遼. See also Bohai 渤海.