| Satomi | |
|---|---|
 Satomiclan emblem | |
| Home province | Kōzuke Province,Awa Province |
| Parent house |  Minamoto clan (Seiwa Genji) Nitta clan |
| Titles | various |
| Founder | Satomi Yoshitoshi |
| Final ruler | Satomi Tadayoshi |
| Founding year | 13th century |
| Ruled until | 1622 |
TheSatomi clan (里見氏,Satomi-shi) was aJapanese samurai clan of theSengoku period (1467–1573) and earlyEdo period (1603–1868). The clan ruledAwa Province as aSengoku daimyō and was a major military power in theKantō region during the wars of theNanboku-chō period. Although confirmed asdaimyō ofTateyama Domain by theTokugawa shogunate.
The Satomi claimed descent from theSeiwa Genji clan viaNitta Yoshishige (d. 1202), whose sonYoshitoshi took "Satomi" as his surname.[1][2]
After the fall of theKamakura shogunate in 1333, theKantō region was high unstable due to incessant conflict between theKantō kubō underAshikaga Shigeuji based in Kamakura and theAshikaga shogunate, represented by theKantō Kanrei underUesugi Noritada. The minor lords of Awa Province (present-day southernChiba Prefecture ) were loyal to theKanrei, but geographically, the province was very near Kamakura, separated only by the narrowUraga Channel. To seize Awa Province, theKantō kubō sent the Satomi clan underSatomi Yoshizane (1412-1488), who landed atShirahama from which he gradually expanded to conquer the province. Satomi Yoshizane claimed to be the chieftain of the Satomi clan, but his ancestry is somewhat uncertain. His descendants are known as at the "Awa Satomi clan", and cadet branches of the clan existed inDewa,Echigo, andMino Province.
In 1516,Odawara-basedHōjō clan defeated theMiura clan and seizedMiura Peninsula, opposite ofUraga Channel from Awa Province. Furthermore, the Hōjō expanded northward alongTokyo Bay, capturingEdo Castle by 1524. This threatened the Satomi clan from west and north. In response,Satomi Yoshitoyo launched anamphibious invasion ofKamakura, in the process of which his forces burned down the famedShinto shrine ofTsurugaoka Hachiman-gu. This was a massive loss of prestige for Yoshitoyo, and led to an internal conflict within the Satomi clan.Satomi Sanetaka, head of a cadet branch of the clan attempted a coup d'état with Hōjō assistance in 1533, but the attempt failed and he was killed. Yoshitoyo then attacked Sanetaka's son,Satomi Yoshitaka, but Yoshitaka escaped and together with the Hōjō and a strong navy, he managed to drive out Yoshitoyo and seize power the following year. He then broke his alliance with the Hōjō and revived the ancient feud between the clans. Soon afterwards, Satomi Yoshitaka seizedKazusa Province and from his base atKururi Castle turned his attention toShimōsa Province. Meanwhile, the Hōjō has taken control ofMusashi Province to the north of Shimōsa. The Hōjō were far stronger, and their armies broke the Satomi forces and even attacked Kururi Castle, but Yoshitaka turned toUesugi Kenshin for assistance and kept his independence. After his death in 1574, Uesugi Kenshin lost all of his territories in the Kantō region and could no longer assist the Satomi. Yoshitaka's son,Satomi Yoshihiro (1530-1578) pledged fealty toHōjō Ujitsuna in 1539 and surrendered the northern half of Kazusa Province. The Satomi were involved in theFirst Battle of Kōnodai (1538) and theSecond Battle of Kōnodai (1564).[3] After his death to illness in 1578, a conflict arose between his son,Satomi Yoshishige and his younger brother,Satomi Yoshiyori. Yoshiyori had the support of the Hōjō and defeated Yoshishige, but the clan was severely weakened. In order to better control commerce and to make better use of their maritime power, he relocated his seat from Kururi toOkamoto Castle.
By 1580, as the situation for clan improved, he builtTateyama Castle. In 1590,Toyotomi Hideyoshi launched a campaign to destroy the Hōjō. Satomi Yoshiyasu quickly attacked the Hōjō strongholds in Kazusa in an arbitrary attempt to recover his former territories. However, as these attacks took place without Hideyoshi's permission or coordination with Toyotomi generals, Hideyoshi was angered, and he subsequently reduced the Satomi clan's holding to only Awa Province. Yoshiyasu relocated his seat from Okamoto to Tateyama Castle. At the beginning of the Edo period the clan was named thedaimyō of Awa Province with akokudaka of 120,000koku under theTokugawa shogunate.[3] However, the clan was implicated in theŌkubo Nagayasu Incident of 1614, andSatomi Tadayoshi (1594–1622) was banished toHōki Province (present-dayTottori Prefecture), and had his holdings reduced to 30,000koku. Tadayoshi had no heir, and the clan died out with his death.[2]
In 2012, the ruins of two early castles in southernBōsō Peninsula,Inamura Castle andOkamoto Castle were collectively designated aNational Historic Site under the nameSatomi clan castle ruins (里見氏城跡,Satomi-shi shiro ato).[4]
The original Tateyama Castle was allowed to fall into ruins upon theattainder of Tateyama Domain in the death of Satomi Tadayoshi in 1622. Although the domain was restored in 1781 underInaba Masaaki, he was not permitted to rebuild the castle, but only to construct ajinya fortified residence. The currenttenshu is a 1982 reconstruction intended to boost local tourism and to function as an annex to the local Tateyama City Museum.