The Battle of the Caucasus is a name given to a series of Axis and Soviet operations in the Caucasus area on the Eastern Front of World War II. On 25 July 1942, German troops captured Rostov-on-Don, Russia, opening the Caucasus region of the southern Soviet Union, and the oil fields beyond at Maikop, Grozny, and ultimately Baku, to the Germans. Two days prior, Adolf Hitler issued a directive to launch such an operation into the Caucasus region named Operation Edelweiß. German forces were compelled to withdraw from the area that winter as Operation Little Saturn threatened to cut them off. North Caucasian Front (Marshal Semyon Budyonny) – until September 1942 Transcaucasian Front (General of the Army Ivan Tyulenev) Black Sea Fleet (Vice Admiral Filipp Oktyabrsky) Azov Sea Flotilla (Rear Admiral Sergey Gorshkov) Army Group A – General Field Marshal (Generalfeldmarschall) Wilhelm List 1st Panzer Army – General Paul von Kleist 17th Army – Colonel-General (Generaloberst) Richard Ruoff 3rd Romanian Army – General Petre Dumitrescu Operation Edelweiss, named after the mountain flower, was a German plan to gain control over the Caucasus and capture the oil fields of Baku on the Eastern Front of World War 2. The operation was authorised by Adolf Hitler on 23 July 1942. The main forces included Army Group A commanded by Wilhelm List, 1st Panzer Army (Ewald von Kleist), 4th Panzer Army (Colonel-General Hermann Hoth), 17th Army (Colonel-General Richard Ruoff), part of the Luftflotte 4 (Generalfeldmarschall Wolfram Freiherr von Richthofen) and the 3rd Romanian Army (General Petre Dumitrescu). Army Group A was supported to the east by Army Group B commanded by Fedor von Bock and by the remaining 4th Air Fleet aircraft (1,000 aircraft in all). The land forces, accompanied by 15,000 oil industry workers, included 167,000 troopers, 4,540 guns and 1,130 tanks. Several oil firms such as "German Oil on the Caucasus", "Ost-Öl" and "Karpaten-Öl" had been established in Germany. They were awarded an exclusive 99-year lease to exploit the Caucasian oil fields.