The clan had three branches; one that originated from Seiwa-Genji (Minamoto clan); one that originated from MINAMOTO no Koreyoshi (Kanja MATSUI) who was from the Tameyoshi line of Seiwa-Genji; and one that originated from MINAMOTO no Mitsumasa.
清和源氏を祖とする松井氏；清和源氏為義流の源維義（松井冠者）を祖とする松井氏と、源満政を祖とする松井氏がある。