Many Spanish Republicans found refuge from the Spanish Civil War in the USSR. The Soviets happily drafted these men when the Germans invaded in 1941. For example Rubén Ruiz Ibarruri, the son of La Pasinaria, commanded a machine gun company of 35th Guards Rifle Division (Beevor, 1999). He was killed south of Kotluban; I think this was in Sep 1942.
Most people don’t realise that although officially neutral Spain had an active part in WW2 in the form of the Blue Division, otherwise known as the Spanish Volunteer Division, Division Azul, or by its official German title of the 250th Infantry Division of the Wehrmacht. Individual Spaniards were also involved on both sides during WWII, often in quite large numbers. In a few cases these individuals were collected into units.
This is a rough outline of the life and times of the Spanish fighting on the Eastern Front during WW2 – the Blue Division. I’ve included some detail about higher level operations to provide context and ditto for nearby operations. The 250th (Blue) Division’s finale was at Krasny Bor. If you’re looking for maps then try here.