The name of Minamoto started when Emperor Saga demoted his 32 Princes and Princesses from nobility to subject and gave them the surname of Minamoto.
源氏は嵯峨天皇が、815年（弘仁5年）に自らの皇子・皇女32名を一挙に臣籍降下させ、源氏を賜ったことに始まる。