Shimazu Clan

Lore & Background

The Shimazu were descendants of the Seiwa Genji branch of the Minamoto. The founder, Shimazu Tadahisa (d. 1227), was a son of Shōgun Minamoto no Yoritomo (1147–1199) with the sister of Hiki Yoshikazu. Tadahisa's wife was a daughter of Koremune Hironobu, a descendant of the Hata clan. He received the domain of Shioda in Shinano Province in 1186 and was then named shugo of Satsuma Province. He went to Satsuma in 1196, subdued the Hyūga and Ōsumi provinces, and built a castle in the Hyūga Province as part of the Shimazu Estate. However, Tadahisa's ambiguous genealogy has caused scrutiny among Japanese historians on whether his lineage was truly Genji, since older sources record him under 'Koremune,' the same clan as his wife. The general consensus is that Tadahisa was of Koremune descent like his wife, and not Seiwa Genji.

In Their Own Story

Shimazu Yoshihisa (1533–1611), the 16th head of the Shimazu family, succeeded in unifying and controlling the entire Kyushu region in 1586. He retired in 1587 after Toyotomi Hideyoshi's Kyushu Campaign. The 17th head, Yoshihiro (1535–1619), was the daimyō at the time of the Battle of Sekigahara, the establishment of the Tokugawa Shogunate, and the Siege of Osaka. His nephew and successor was Tadatsune. He organized the Shimazu invasion of the Ryūkyū Kingdom (modern-day Okinawa Prefecture) in 1609. The Shōgun allowed this because he wished to appease the Shimazu and prevent potential uprisings after their loss at Sekigahara. The trade benefits thus acquired, and the political prestige of being the only daimyō family to control an entire foreign country secured the Shimazu's position as one of the most powerful daimyō families in Japan at the time.

Reader's Guide

The Shimazu clan was renowned for the loyalty of its retainers and officers, especially during the Sengoku period. Some retainer families, such as the Ijuin and Shirakawa, were determined to defeat any opposition to help expand the power of the Shimazu clan. The Shimazu are also famous for being the first to use teppo (firearms, specifically matchlock arquebuses) on the battlefield in Japan, and began domestic production of the weapons as well. Shimazu battle tactics are known to have been very successful in defeating larger enemy armies, particularly during their campaign to conquer Kyūshū in the 1580s. Their tactics included the luring of the opposition into an ambush on both sides by arquebus troops, creating panic and disorder. Central forces would then be deployed to rout the enemy. In this way, the Shimazu were able to defeat much larger clans such as the Itō, Ryūzōji and Ōtomo. Overall, the Shimazu was a very large and powerful clan due to their strong economy both from domestic production through trade, good organization of government and troops, strong loyalty of retainers and isolation from Honshū.

Did You Know?

• The Shimazu were the first to use teppo (firearms, specifically matchlock arquebuses) on the battlefield in Japan, and began domestic production of the weapons as well.
• At their peak, the Shimazu were the wealthiest and most powerful Tozama daimyō family with an income in excess of 700,000 koku.
• The Shimazu were the only daimyō family to control an entire foreign country, the Ryūkyū Kingdom, after their invasion in 1609.
• The general consensus among historians is that the clan's founder, Shimazu Tadahisa, was of Koremune descent, not Seiwa Genji as he claimed.