Polish 1st Legions Infantry Division is a tactical unit of the Polish Army. Formed on February 20, 1919, partially of veterans of the I Brigade of the Polish Legions, the unit saw extensive action during the Polish-Bolshevik War and World War II. Regarded by the soldiers of the Wehrmacht as the Iron Division, it distinguished itself in the Invasion of Poland.

The Land Forces are the land forces of the Polish Armed Forces. They currently contain some 100,000 active personnel and form many components of the European Union and NATO deployments around the world. Poland's recorded military history stretches back a millennium – since the 10th century. Poland's modern army was formed after Poland regained independence following World War I in 1918.