The Asano or Assano clan (淺野氏 Asano-shi) was a samurai clan of feudal Japan that controlled the han (fiefdom) of Hiroshima around Hiroshima Castle for much of the Edo Period.
The Asano descend from Emperor Seiwa (850-880) and Minamoto no Yorimitsu (944-1021), and are a branch of the Toki family.
Minamoto no Mitsunobu, a fourth generation descendant of Yorimitsu, settled in Toki (Mino) and took for himself the name of the place. The Toki were hereditary shugo (governors) of Mino province until the 16th century.
Perhaps the name Asano is best known as a result of the history of the 47 rōnin, whose lord was Asano Naganori, of the main branch of the clan in Ako (Harima Prefecture, 53000 koku).
The Asano were tozama daimyō, or "external lords," who had no hereditary ties to the Tokugawa shogunate. Thus they had various responsibilities and obligations to the shogun at a higher level than other lords.
Furthermore, the clan's castle city was Hiroshima, with its large harbor, and the clan ruled the provinces of Aki and Bingo, totaling an income of 426500 koku.
Principal members of the Asano clan
- Asano Nagamasa (1546-1610), brother-in-law of Toyotomi Hideyoshi, fought for him in Japan and Korea.
- Asano Yoshinaga (1576-1613), son of Nagamasa. He also served Hideyoshi in campaigns in Japan and Korea.
- Asano Nagaakira (1586-1632), brother of Yukinaga, first Asano daimyo of Hiroshima.
- Asano Naganori (1667-1701), lord of the 47 rōnin.
- For a list of other Asano lords in Hiroshima, see Hiroshima Castle.