The Allied intervention was a multi-national military expedition launched in 1918 during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 which continued into the Russian Civil War

Russian Civil War

The Russian Civil War was a multi-party war that occurred within the former Russian Empire after the Russian provisional government collapsed to the Soviets, under the domination of the Bolshevik party. Soviet forces first assumed power in Petrograd The Russian Civil War (1917–1923) was a...

. Its operations included forces from 14 nations and were conducted over a vast territory. The initial stated goals were to help the Czechoslovak Legions

Czechoslovak Legions

The Czechoslovak Legions were volunteer armed forces composed predominantly of Czechs and Slovaks fighting together with the Entente powers during World War I...

, secure supplies of munitions and armaments in Russian ports, and re-establish the Eastern front

Eastern Front (World War I)

The Eastern Front was a theatre of war during World War I in Central and, primarily, Eastern Europe. The term is in contrast to the Western Front. Despite the geographical separation, the events in the two theatres strongly influenced each other...

. After winning the war in Europe, the Allied powers

Allies of World War I

The Entente Powers were the countries at war with the Central Powers during World War I. The members of the Triple Entente were the United Kingdom, France, and the Russian Empire; Italy entered the war on their side in 1915...

 militarily backed the pro-Tsarist

Nicholas II of Russia

Nicholas II was the last Emperor of Russia, Grand Prince of Finland, and titular King of Poland. His official short title was Nicholas II, Emperor and Autocrat of All the Russias and he is known as Saint Nicholas the Passion-Bearer by the Russian Orthodox Church.Nicholas II ruled from 1894 until...

, anti-Bolshevik

Bolshevik

The Bolsheviks, originally also Bolshevists , derived from bol'shinstvo, "majority") were a faction of the Marxist Russian Social Democratic Labour Party which split apart from the Menshevik faction at the Second Party Congress in 1903....

 White forces

White movement

The White movement and its military arm the White Army - known as the White Guard or the Whites - was a loose confederation of Anti-Communist forces.The movement comprised one of the politico-military Russian forces who fought...

 in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.