The Duchy of Bohemia, also later referred to in English as the Czech Duchy, was a monarchy and a principality of the Holy Roman Empire in Central Europe during the Early and High Middle Ages. It was formed around 870 by Czechs as part of the Great Moravian realm. Bohemia separated from disintegrating Great Moravia after Duke Spytihněv swore fealty to the East Frankish king Arnulf in 895.

The Czechs, or the Czech people, are a West Slavic ethnic group and a nation native to the Czech Republic in Central Europe, who share a common ancestry, culture, history, and the Czech language.