Move the slider to any year: every territory recorded for that year is drawn. Bohemia and the Czech lands are red; the other lands of the Bohemian crown or the Czech state are orange; lands joined only through the king (personal union) and tributary or uncertain lands are hatched in gold; rival kings and allied states are violet or teal; occupied territory and land lost at that date are hatched; neighbouring powers are grey. 27 chapters carry the story, from the Celtic Boii in 300 BCE to the Czech Republic in 1993. Borders change only where the dataset records a change, and they fade rather than morph between dated shapes. The slider is stretched so that the dense twentieth century gets more room than the long early centuries. Hover a territory for its name and role; click it to open its Wikipedia article.

Czech-state shapes are built from modern administrative units that approximate the historical lands (Bohemia, Moravia, Silesia, the Lusatias, Brandenburg, the Alpine duchies), so medieval frontiers are only approximate. The shapes of Samo's realm, Great Moravia, "New Bohemia" and the lines of 1938–1939 are especially uncertain, and Great Moravia's reach into Bohemia, Silesia and Pannonia is shown as tributary or uncertain, not as core territory. The dashed line shows today's border of the Czech Republic for orientation.