Iruma Prefecture

The following year, the area was divided into Saitama, Shinagawa, and Kosuge prefectures), Shimosasa prefectural governor (previously Katsushika prefecture), Iwanami prefecture, and Nirayama prefecture, but there was still a complex mix of Oshi, Iwatsuki, Kawagoe, and other exclaves such as Hanbara, Maebashi, and Takasaki domains that had existed since the end of the Edo period. In 1671, the various prefectures were abolished and established as prefectures, and the area was divided into Saitama prefecture (Saitama district and parts of Adachi and Katsushika districts) centered on the areas under the jurisdiction of Urawa (formerly Omiya prefecture), Oshi, and Iwatsuki prefectures, and Iruma prefecture (13 districts including Niiza and parts of Tama district) centered on the areas under the jurisdiction of Kawagoe and Hanbara prefectures, but in 1673, Iruma prefecture was merged with Gunma prefecture to become Kumagaya prefecture. In 1875, Saitama Prefecture incorporated part of Katsushika County, Chiba Prefecture, and transferred part of Adachi County to Tokyo Prefecture. The following year, when Kumagaya Prefecture was abolished, it annexed the former Iruma Prefecture, and the current prefectural boundaries were more or less finalized.

*Some of the terminology that refers to "Iruma Prefecture" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…翌年支配地は埼玉，品川，小菅3県に分割)，下総知県事(同前，葛飾県)，岩鼻県，韮山県の管轄地となったが，なお幕末以来の忍（おし）藩，岩槻藩，川越藩，および半原藩，前橋藩，高崎藩などの飛地が錯綜していた。71年廃藩置県を経て諸県は統合され，荒川を境に浦和(大宮県が改称)，忍，岩槻3県の管轄地を中心とした埼玉県(埼玉郡と足立･葛飾両郡の一部)と，川越，半原2県の管轄地を中心とした入間（いるま）県(新座以下13郡と多摩郡の一部)に二分されたが，73年入間県は群馬県と合併して熊谷県となった。75年埼玉県は千葉県葛飾郡の一部を編入，足立郡の一部を東京府へ移管し，さらに翌年熊谷県の廃県に伴い旧入間県域を併合して，ほぼ現在の県域が確定した。…

※「入間県」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