《北史·本记·卷一》
登国元年春正月初六，道武帝即位，称代王。郊祀天帝，建年号，大会各部落首领于牛川。
登国元年春正月戊申，帝即代王位，郊天建元，大会于牛川。
On the first day of the first month of spring in the first year of Dengguo, Emperor Daowu ascended the throne and called himself King Dai. He offered sacrifices to the emperor of heaven, established the reign name, and held a grand meeting of the leaders of each tribe in Niuchuan.