Adachi

Adachi lies at the northern edge of Musashi Province, where the Sumida and Arakawa rivers divide the plain into low, flood-prone districts. Under the Ritsuryō system the area formed the southern part of Adachi District. The rivers supplied water and transport but frequently changed their channels, forcing settlements onto small levees and higher ground. Reed marshes and cultivated fields occupied much of the land between the rivers.

Nishiarai Daishi was founded as a Shingon temple in 826 and became one of the important Buddhist centres of the Kantō region. Pilgrimage and temple estates drew people across the river plain. During the Muromachi and Sengoku periods, the Chiba clan held influence over the district while local families defended small forts and cultivated holdings.

By the Edo period, Senju had become the district's principal settlement. The Great Senju Bridge was completed in 1594, and Senju-shuku developed as a post station on both the Nikkō and Mito roads. The Tokugawa shogunate controlled parts of the area directly, while Kan'ei-ji administered other lands. River crossings, markets and temple patronage gave Adachi a stable place on the northern approach to Edo, even while floods repeatedly altered the surrounding fields.