Until 1948, Bohemia was an administrative unit of Czechoslovakia as one of its "lands" ("země"). Since then, administrative reforms have replaced self-governing lands with a modified system of "regions" ("kraje") which do not follow the borders of the historical Czech lands (or the regions from the 1960 and 2000 reforms). However, the three lands are mentioned in the preamble of the Constitution of the Czech Republic: "We, citizens of the Czech Republic in Bohemia, Moravia and Silesia…"
Much later Roman authors refer to the area they had once occupied (the "desert of the Boii" as Pliny and Strabo called it) as Boiohaemum. The earliest mention was by Tacitus' Germania 28 (written at the end of the 1st century AD), and later mentions of the same name are in Strabo and Velleius Paterculus. The name appears to include the tribal name Boi- plus the Germanic element *haimaz "home" (whence Gothic haims, German Heimat, English home). This Boiohaemum was apparently isolated to the area where King Marobod's kingdom was centred, within the Hercynian forest.
The Czech name "Čechy" is derived from the name of the Slavicethnic group, the Czechs, who settled in the area during the 6th or 7th century AD.