The Shimazu Estate (島津荘, Shimazu no shō) was a shōen (estate or manor) in southern Kyushu of Japan. It was the largest shōen of medieval Japan. The Shimazu clan was named after this estate as the clan succeeded the position of jitō (land steward).
History
No contemporary source recorded the foundation of the Shimazu Estate. According to a document dated circa 1291, a "wasteland belonging to no one" was developed during the Manju era (1024–1028) and was donated to Kampaku (de facto ruler of Japan) Fujiwara no Yorimichi. Another document states that its founder was Taira no Suemoto, the Dazai Daigen (high-ranking official of the administrative center of Kyūshū). It is likely that Taira no Suemoto was the founder of the Chinzei Heishi, a branch line of the Taira clan in Kyushu. A notable member of the Chinzei Heishi was Ata Tadakage.
The Shimazu Estate originally covered Shimazu, Hyūga Province (modern-day Miyakonojō, Miyazaki Prefecture) but was soon expanded into the neighboring lands of the province. Under the patronage of the powerful Fujiwara clan, Taira no Suemoto exercised effective administrative control over the lands. In 1029, Taira no Suemoto even raided the government office of the neighboring Ōsumi Province but a fragmentary sources suggest that he was not punished severely.
The Shimazu Estate was expanded substantially in the first half of the 12th century. Large portions of Satsuma, Ōsumi (including the island of Tanegashima) and southern Hyūga became part of the estate, either as ichien no shō (estate under complete control) or yose gōri (where tax revenue was shared with the provincial government).
The Shimazu Estate came under the control of the Taira clan in the second half of the 12th century because Taira no Moriko, a daughter of Taira no Kiyomori, managed the property of the Fujiwara clan after her husband Kampaku Fujiwara no Motozane died in 1166. After Moriko's death, the estate was inherited by the Konoe branch family of the Fujiwara clan.
With the establishment of the Kamakura shogunate, supporters of the Taira clan were replaced by the shogun's retainers. In 1185, Koremune no Tadahisa was appointed as jitō of the Shimazu Estate. Although he was originally a retainer of the Konoe family, he moved in an inner circle of the shogunate for his kinship ties with the first shogun Minamoto no Yoritomo and his powerful retainer Hiki Yoshikazu. He was also appointed as Governor of Satsuma, Ōsumi and Hyūga Provinces. Thereafter he claimed the clan name of Shimazu. A small portion of the Shimazu Estate in Satsuma was controlled by the Chiba clan.
In 1203, Shimazu Tadahisa was ousted from his positions as a jitō of the estate and the governor of the three provinces because his relative Hiki Yoshikazu was annihilated by the Hōjō clan. He managed to regain the posts of the jitō of the Shimazu Estate in Satsuma and the Governor of Satsuma Province. However, the jitō of the estate in Ōsumi and the Governor of Ōsumi Province were succeeded by the Hōjō clan. The Nagoe branch family of the Hōjō clan sent the Higo clan to Ōsumi as deputy rulers. After the Hōjō clan was annihilated, one line of the Higo clan made itself autonomous in Tanegashima and began to claim the clan name of Tanegashima. It was during the Kenmu Restoration that the Shimazu clan won back the jitō of the Shimazu Estate in Ōsumi and the Governor of Ōsumi and Hyūga Provinces.