World War II: Units of 1st Czechoslovak Army Corps crossed Czechoslovak borders during Battle of the Dukla Pass.
The Battle of the Dukla Pass, also known as the Dukla, CarpathoDukla, RzeszwDukla, or DuklaPreov offensive, was the battle for control over the Dukla Pass on the border between Poland and Slovakia on the Eastern Front of World War II between Nazi Germany and the Soviet Union in SeptemberOctober 1944. It was part of the Soviet East Carpathian strategic offensive that also included the CarpathianUzhgorod offensive. The operation's primary goal, to provide support for the Slovak rebellion, was not achieved, but it concluded the full liberation of the Ukrainian SSR.
The German resistance in the eastern Carpathian region was much stronger than expected. The battle which began on 8 September would not see the Soviet forces on the other side of the pass until 6 October, and German forces would stop their heavy resistance in the region only around 10 October. Five days to Preov turned into fifty days to Svidnk alone with over 70,000 casualties on both sides. Preov that was to be reached in six days remained beyond the Czechoslovaks' grasp for four months. The battle would be counted among the most bloody in the entire Eastern Front and the history of Slovakia; one of the valleys in the pass, near the villages of Kapiov, Chyrowa, Iwla and Gojsce, would become known as the "Valley of Death".
The 1st Czechoslovak Army Corps (Czech: První československý armádní sbor, Slovak: Prvý československý armádny zbor), also known as Svoboda's Army (Czech: Svobodova armáda, after its commander Ludvík Svoboda), was a military formation of the Czechoslovak Army in exile fighting on the Eastern Front alongside the Soviet Red Army in World War II.The corps was the largest of the Czechoslovak units that fought on the Soviet side on the Eastern Front.