The current Czech Republic comprises 3 historical lands: Bohemia (Čechy) in the west, Moravia (Morava) in the southeast, and Czech Silesia (Slezsko; the smaller, south-eastern part of historical Silesia, most of which is located within modern Poland) in the northeast. Jointly, these historic regions are described as “Czech lands” (former “Lands of the Bohemian Crown”), with the Czech language being spoken in all three. When the Czech nation regained its independence in 1918, the new state of Czechoslovakia was constituted to reflect the union of the Czech and Slovak territories that were merged together after World War I (in addition, a small western part of present Ukraine was included as well).
The word Czech came into English later via Polish. The current English spelling is similar to an antiquated Czech spelling (Cžechy, Cžech), however it is unlike the modern Čechy and Česko. This discrepancy arises from a 15th century reform of Czech priest Magister John Huss.