Oe clan (大江氏)
The Oe clan were nobles from ancient times until early modern times. The name "Oe" is a Sei (or Honsei) which is a family name representing a large group of blood relatives, such as Minamoto, Taira, Fujiwara, and Tachibana; it is not a Myoji, which is a family name originating from the name of the region from which the person came or the job the person does.
It is said that the Haji clan in ancient times was their origin. In 791, Emperor Kanmu, in the tenth year of his reign, gave OE no Morogami, with whom the Emperor was a relative, gave the Sei of Oe.
In 866, OE no Otondo (大枝音人) changed Sei and became OE no Otondo (大江音人)
The Oe clan had many excellent kajin (waka poets) and academia's and they were given important posts by the Imperial Court. Thirty-six excellent waka poets called "chuko-sanjurokkasen,"OE no Chisato (wakanpoet), OE no Masahira, OE no Yoshitoki, and from ladies, Izumi Shikibu, Akazome Emon, were chosen from the Oe clan. As a grandson of OE no Masahira, there was OE no Masafusa, who was one of the best acedemia in the Heian Period and reportedly taught the art of warfare to MINAMOTO no Yoshiie (Hachimantaro Yoshiie) of Kawachi-Genji (Minamoto clan).
OE no Hiromoto, who served MINAMOTO no Yoritomo, the head of the Kawachi-Genji, was a grandson of OE no Masafusa and supported Yoritomo's achievements from the aspect of domestic administration. When Yoritomo opened the Kamakura bakufu (Japanese feudal government headed by a shogun), Hiromoto rose to the nerve center of the bakufu. Because of this, the line of OE no Hiromoto became the OE clan, the origin of samurai families including the Mori clan.
Because OE no Suemitsu (Suemitsu MORI), the fourth son of OE no Hiromoto, supported Yasumura MIURA who raised a rebellion against the Kamakura bakufu, the direct line of the Oe clan as samurai family declined.
The Mori clan in Aki Province and Izumo Province
The Kaito clan, Sakai clan, and Yasuda clan in Mikawa Province
The Echigo-Hojo clan, and Yasuda clan in Echigo Province
The Sagae clan, and Nagai clan in Dewa Province
The Nawa clan in Kozuke Province
The Descendants of Masanori, Hiromoto's elder brother, remained as officials of the Imperial court and called themselves the Kitakoji family from the end of the Muromachi period and, during the Edo Period, three families (two as kurodo - chamberlain and one as Shodaibu [aristocracy lower than Kugyo] of the Konoe family) appeared as Jige-ke (family status of non-noble retainers who are not allowed into the Emperor's living quarters in the imperial palace). Among them, two families which served as kurodo for generations were promoted to toshoke (the hereditary lineage of Court nobles occupying relatively high ranks) (hanke [lowest rank for toshoke] [kuge - court nobles]) on January 22, 1848 duging the last stage of the Edo Period (last promotion to toshoke).