Nagara was born as the eldest son of the sadaijin Fujiwara no Fuyutsugu, a powerful figure in the court of Emperor Saga.

However, after Ninmyō took the throne, Nagara's advancement was overtaken by his younger brother Fujiwara no Yoshifusa.

He served as director of the kurōdo-dokoro (蔵人所) and division chief (督) in the imperial guard before finally making sangi and joining the kugyō in 844, ten years after his younger brother.

In 877, after her son Prince Sadaakira took the throne as Emperor Yōzei, Nagara was posthumously promoted to shō ichi-i (正一位) and sadaijin, and again in 879 to daijō-daijin.

His third son Fujiwara no Mototsune was adopted by Yoshifusa, and his line branched into various powerful clans, including the five regent houses.