The Duchy of Bohemia, also referred to as the Czech Duchy, (Czech: České knížectví) was a monarchy and a principality in Central Europe during the Early and High Middle Ages. It was formed around 870 by Czechs as part of the Great Moravian realm. The Bohemian lands separated from disintegrating Moravia after Duke Spytihněv swore fidelity to the East Frankish king Arnulf in 895.
While the lands were occupied by the Polish king Bolesław I and internal struggles shook the Přemyslid dynasty, Duke Vladivoj received Bohemia as a fief from the hands of the East Frankish king Henry II in 1002 and the duchy became an Imperial State of the Holy Roman Empire. The Duchy of Bohemia was raised to a hereditary Kingdom of Bohemia, when Duke Ottokar I ensured his elevation by the German king Philip of Swabia in 1198. The Přemyslids remained in power throughout the High Middle Ages, until the extinction of the male line with the death of King Wenceslaus III in 1306.
The Kingdom of Bohemia, sometimes in English literature referred to as the Czech Kingdom (Czech: České království; German: Königreich Böhmen; Latin: Regnum Bohemiae, sometimes Regnum Czechorum), was a medieval and early modern monarchy in Central Europe, the predecessor of the modern Czech Republic. It was an Imperial State in the Holy Roman Empire, and the Bohemian king was a prince-elector of the empire. The kings of Bohemia, besides Bohemia, ruled also the Lands of the Bohemian Crown, which at various times included Moravia, Silesia, Lusatia and parts of Saxony, Brandenburg and Bavaria.
The kingdom was established by the Přemyslid dynasty in the 12th century from Duchy of Bohemia, later ruled by the House of Luxembourg, the Jagiellonian dynasty, and since 1526 by the House of Habsburg and its successor house Habsburg-Lorraine. Numerous kings of Bohemia were also elected Holy Roman Emperors and the capital Prague was the imperial seat in the late 14th century, and at the end of the 16th and beginning of the 17th centuries.
After the dissolution of the Holy Roman Empire in 1806, the territory became part of the Habsburg Austrian Empire, and subsequently the Austro-Hungarian Empire from 1867. Bohemia retained its name and formal status as a separate Kingdom of Bohemia until 1918, known as a crown land within the Austro-Hungarian Empire, and its capital Prague was one of the empire's leading cities. The Czech language (called the Bohemian language in English usage until the 19th century) was the main language of the Diet and the nobility until 1627 (after the Bohemian Revolt was suppressed). German was then formally made equal with Czech and eventually prevailed as the language of the Diet until the Czech national revival in the 19th century. German was also widely used as the language of administration in many towns after Germans immigrated and populated some areas of the country in the 13th century. The royal court used the Czech, Latin, and German languages, depending on the ruler and period.
Following the defeat of the Central Powers in World War I, both the Kingdom and Empire were dissolved. Bohemia became the core part of the newly formed Czechoslovak Republic.