The Czech series #4 - The Czechoslovak Legion (1)

The Czechoslovak Legions were Czech and Slovak volunteer armed forces fighting together with the Entente powers during World War I. Their goal was to win the Allies' support for the creation of an independent country of Czechoslovakia, which was then part of the Austro-Hungarian Empire. The Legions originated with small armed units organized from 1914 onwards by volunteer Czechs and Slovaks. Later, many Czechs and Slovaks captured during the war joined these units; with help of émigré intellectuals and politicians (Tomáš Masaryk, Milan Rastislav Štefánik and others) the Legions grew into a force of tens of thousands. The independence of Czechoslovakia was finally obtained in 1918.

After three years of existence as a small brigade in the Imperial Russian Army (Česká družina), the Czechoslovak Legions in Russia were created in 1917. Other units had been fighting in France since the war's beginning (including volunteers from the US), and later in Italy and Serbia. Their membership consisted of Czech and Slovak prisoners of war in Russia, Serbia and Italy, and Czech and Slovak emigrants in France and Russia who had already created the "Czech company" in Russia and a unit named "Nazdar" in France in 1914. The Legions were actively involved in many battles of World War I, including Vouziers, Arras, Zborov, Doss Alto, Bakhmach, and others. They were also important in the Russian Civil War.

The vast majority (around 90%) of the legionaries were Czechs. Slovaks made up 7.4% in the Russian legions, 3% in the Italian and 16% in the French.

The term "Legions" was not widely used during the war but was adopted shortly afterward. It is primarily based on their French connection – they reported to France and were, in a general way, thought of as related to the French Foreign Legion.

The Legions are traditionally called the Czech Legion (singular) in English.