Seiwa Genji
Mitsunaka's association with Fujiwara clan made him one of the richest and most powerful courtiers of his day. He served as the acting governor (kokushi) of ten provinces, most notably Settsu, which became the mainstay of his military and economic power. In addition, Mitsunaka inherited his father's title of "Chinjufu-shōgun", Commander-in-chief of the Defense of the North. The patron/client relationship between the Fujiwara and the Seiwa Genji continued for nearly two hundred years after Mitsunaka's death; indeed, the Seiwa Genji came to be known as the "teeth and claws" of the Fujiwara.