Formed by Poles serving in the tsarist army during World War I, the Polish Legions ("Pol'skie Legiony") occupy a unique and exalted role in Poland's history.

The Polish Legions ("Pol'skie Legiony") were formed in June 1917 by Poles serving in the tsarist army. In the wake of the 1917 October coup, they resisted the Bolsheviks' attempts to establish Soviet rule in Ukraine. Their aspirations for reviving the Polish state, incorporating considerable territories of land in western Ukraine, made German and Austrian military commanders uneasy. Eventually, some of the Polish Legions were defeated; others were disbanded, ending this unique episode of the Polish independence movement.

The collection includes the organization and stationing of Polish military units in Petrograd in 1917-1918, correspondence between the Warsaw-based Regency Council, General Skoropadsky, and the government of the Ukrainian National Republic, alphabetically arranged rolls of military personnel, lists of Polish officers up for decorations and orders, and other documentary materials.

For more than 70 years, the very existence of this collection was a closely guarded secret. Evacuated to the Urals during the Great Patriotic War, the collections were returned but archived only in 1960. It was not until 1990 that the collection was declassified.

Despite the wealth of information, the materials have been used only superficially for research. Because the documents are authentic, researchers now have even deeper insight into this little known episode in Polish-Ukrainian history. The collection offers potential to genealogical researchers.