With the dawning of the Edo period, peace came and the defensive role of castles was gradually changed to the role as government offices; thus, the role of Tenshu was also finished, and Goten and Ninomaru/Sannomaru were gradually expanded in castles.
江戸期になり平和な時代が訪れると、城は防衛の役目を終え政庁へと変化していったので、天守の役目も終わり、城は次第に御殿や二の丸・三の丸が拡充されていった。