Britannica Sources used in this answer

Why did Tokugawa Ieyasu require daimyo to help build Edo Castle?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Statue of Tokugawa Ieyasu in ornate robes holding a bow, with arrows on his back, at the Tosho-gu shrine in Nikko, Japan. — Tokugawa Ieyasu Statue of Tokugawa Ieyasu at the Tōshō Shrine in Nikkō, Japan.

Tokugawa Ieyasu required daimyo to assist in the construction and expansion of Edo Castle primarily as a strategic method to maintain control over them and ensure the stability of his newly established shogunate.12

By mandating that these lords contribute to major public works within the shogunal domains, Ieyasu kept the daimyo in a state of financial difficulty, which limited their ability to accumulate the wealth or resources necessary to challenge his authority. This practice was part of a broader effort to consolidate power following the Battle of Sekigahara, alongside other measures such as land transfers and the eventual implementation of the sankin kotai (alternative attendance) system. Through these requirements, Ieyasu effectively weakened potential rivals while simultaneously building a massive, fortified center of government that symbolized his undisputed mastery of Japan.21