Karpaty Army (Polish: Armia Karpaty), formed on 11 July 1939 under Major General Kazimierz Fabrycy, was created after Germany had annexed Czechoslovakia and created a puppet state of Slovakia. According to Polish historians Czesław Grzelak and Henryk Stańczyk, it consisted of two mountain brigades, Lwów Brigade of National Defence and a Battalion Węgry (Hungary). Altogether, Karpaty Army was made of 26 battalions, 160 cannons and 16 planes.
The main task of the army was to secure mountain passes in the Carpathians from Czorsztyn to Polish-Romanian border (total length 350 kilometers), and to protect the Centralny Okręg Przemysłowy industrial region. Furthermore, it was tasked with protection of southern wing of Kraków Army, and the oil-rich area of Borysław and Drohobycz. In late August 1939, concentration of Karpaty Army was not yet completed, as it was to be fully operational only after the complete of mobilization of the Polish Army. Karpaty Army was the weakest of all Polish armies in 1939, lacking heavy equipment, and manned by older officers. Since first hours of the war, Karpaty Army faced well-prepared Alpine German divisions, whose superiority was obvious.
Initially the army consisted of two improvised mountain brigades and a number of smaller units, but later in the course of war (on September 6) it was joined by forces of the withdrawing Armia Kraków, and renamed Armia Małopolska. From 11 September 1939, it was commanded by General Kazimierz Sosnkowski (after General Fabrycy was reassigned to command the Polish Southern Front). On September 1 in the morning, Karpaty Army was attacked in the area of Czorsztyn by the 4th Light Division of the Wehrmacht, supported by the 2nd Mountain Division. Backed by the Slovakian units (see Slovak invasion of Poland (1939)), German divisions managed to break through Polish positions near Tymbark and Limanowa, causing a gap between Karpaty Army and the retreating Kraków Army. As a result, Polish headquarters agreed for a withdrawal. In the first days of the invasion, Karpaty Army lacked reserve units, as its main forces, the 24th I.D., and the 11th I.D. were either still mobilized, or were on their way towards the area of Tarnów.
- 2nd Mountain Brigade (2 Brygada Górska)
- 3rd Mountain Brigade (3 Brygada Górska)
- Carpathian Half-Brigade of National Defence (Karpacka Półbrygada ON)
- 1st Regiment of the Border Defence Corps
- 1st Motorized Artillery Regiment
- 9th Heavy Artillery Regiment
Additionally, mobilisation plans called for creation of the Tarnów Group consisting of:
On 4 September the Army was strengthened by reserve units: