Move through the 42 chapters: each shows every polity recorded for its year. The Japanese state is gold, from the Wa statelets and Yamato to the shogunates, the Empire and today’s Japan; rival Japanese powers (the Northern Fujiwara, the Western Army of 1600, the shogunate loyalists of 1868) are a lighter gold. The Empire’s colonies and leased lands are copper, its occupied lands and puppet states hatched copper. The Ryukyu kingdoms are violet, hatched with gold while Ryukyu was a vassal of Satsuma and then a Japanese domain (1609–1879); the Emishi, Kumaso and Ainu lands are hatched sand; US-administered islands after 1945 are blue. Other powers named in the chapter are green, everything else grey. Borders are drawn for the chapter years only and fade from one chapter to the next. Hover a territory for its name and dates; click it to open its Wikipedia article.

Boundaries are approximate reconstructions. Before about 540 there are no recorded borders: the Wa statelets, the Yamatai confederation and Yamato are drawn from the spread of keyhole tombs and inscriptions, and the Jōmon, Yayoi, Epi-Jōmon, Satsumon and Okhotsk cultures are culture areas with a dashed outline. The Emishi, Kumaso and Ainu lands are the parts of their islands not held by a state at the time. Interior borders between rivals (1600, 1868) are coarse, and the wartime occupation lines are yearly snapshots. The Kurils and southern Sakhalin are drawn as they were actually held; the red dashed line from 1952 is Japan’s claim to the Northern Territories. The white dashed line is Japan’s border today, for orientation only.