Oorusui - Oorusui

Japanese: 大留守居 - おおるすい

...a person who manages a castle in place of the lord while he is away. They are called rusuikogashira (head of the castle) or o-rusuiko (big-lord of the castle). As the power of daimyo expanded during the Sengoku period, they began to directly control strategic castles that had previously been provided to their vassals, and the old vassals who were put in charge of managing and guarding the castles were called jōdai (castle lords).

From 【House Sitter】

…In charge of policing the Ooku, they managed the issuance of passports for women entering the various checkpoints. In the early days, the Shogun was often away from Edo Castle, so their position was important, and they appointed a senior retainer of the genro class as the "O-rusu-i," giving him overall command of the Edo Castle guards while the Shogun was away, and sometimes even in peacetime they were in charge of government affairs as one of the senior retainers. In the early days, they also had an important role in managing the custody of the "witnesses" who were registered by the various daimyo as hostages with the Shogunate and lived in their Edo domain residences. …

*Some of the terminology explanations that refer to "Orusuui" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…城主の留守中に代わって城を管理する者。留守居頭，大留守居などという。また，戦国期の大名権力の拡大に伴い，それまで家臣に給付していた要衝の城を大名が直接支配するようになり，城の管理･守衛をさせた老臣を城代と称した。…

【留守居】より

…大奥の取締りに当たり，諸関所女通行手形の発行を管理した。初期には将軍が江戸城を離れることも多かったので，その地位も重く，元老級の譜代の老臣を〈大留守居〉に任命し，将軍留守中は江戸城守衛の総指揮権を与え，平時も老臣の一員として政務を担当させることもあった。また初期には諸大名が人質として幕府に登録し，江戸藩邸に常住させた〈証人〉の身柄を管理するのも重要任務であった。…

※「大留守居」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典第２版について | 情報

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