Muchimaro became the head of Ministry of Civil Services in 718. When Fuhito, Muchimaro's father, died in 720, Prince Nagaya was at the highest rank in the state government. Prince Nagaya was grandson of Emperor Temmu, but not a son of Fujiwara family, therefore was seen as a threat by Muchimaro and his three brothers. After successfully removing Prince Nagaya in 729, Muchimaro rose to Counselor.
In 734, he was promoted to Udaijin or "Minister of the Right". In 737, he was made Sadaijin or "Minister of the Left", but died of smallpox the following day.
In the 13th century, the main line of the Fujiwara family split into five families or houses: the Kujō, Nijō and Ichijō (descendants of Kanezane); and also the Konoe and Takatsukasa (descendants of Motozane).