Japanese Daimyo Domain System

Timeline

1. 1467–1520Around Kyoto · KinkiAfter the Ōnin War, shugo daimyo and emerging kokujin groups established autonomy within their territories, creating a "gekokujō" pattern; the domain became the de facto political unit and shogunal authority existed in name only.
2. 1520–1550Owari Province · Chūbu RegionStone castles and castle-town commercial districts expanded; daimyo used land surveys to fix annual rice tribute and allocated land to retainers as chigyō, with domain finance and military mobilization systems becoming increasingly institutionalized.
3. 1551–1560Kiyosu Castle, Owari Province · Aichi PrefectureAfter succeeding as head of the Oda house, Oda Nobunaga implemented a unified domain tax system and organized arquebus units; amid the decline of the Imagawa clan, powerful daimyo used their domains as bases to advance toward regional hegemony, and the domain system entered the stage of wars of unification.