The Water Transportation in the Kanto Plain and the "Piracy" there (5)

     Anyway, the Yanada Family was from Yanada Holy Manor, and called themselves Yanada.  The family must have been good at cultivating wetland into fields and maintaining those wet fields, or drainage.  Sometime in the Kamakura Period (1185-1333), they moved to Shimokobe Manor in Katsushika County, Shimousa Province.  “Shimokobe” literally meant a lower-stream riverbank, and the name indicates that the place used to be at the estuary of Tone and Watarase Rivers into Edo Bay.  In the area before the establishment of the manor, natural levees had been formed, and people had started living on them.  By the Kamakura Period, people had built man-made banks, and made hamlets and fields.  The Shimokobe Family became the developer lord of the manor.  As the family’s power weakened, the Hojo Regency made them their vassal and gained control of the manor.  It is recorded that, in 1253, the Kamakura Shogunate government, which was actually being controled by the Hojo Regency, repaired the banks there.

     After the collapse of the Kamakura Shogunate, Yanada Mitsusuke (1395-1438) established the family’s control over Shimokobe Manor, based in Mizuumi Castle.  The control included toll and tax collection at the most important river checkpoints in the Kanto Plain.  That is, the family snatched the power which Katori Shrine might have enjoyed in ancient times, only in the area though.  In that way, the semi-governmental piracy Katori Shrine used to wield could have been decentralized around the plain.

     The Yanada Family owned Mizuumi and Sekiyado Castles in Shimokobe Manor for generations. The two castles were only about 4 kilometers away from each other.  The area was a junction between the 2 river systems which flowed to 2 major inland seas of the region, Edo Bay and Katori Sea.