Operation Schwarz (German: Unternehmen Schwarz), also known as the Fifth Enemy Offensive (Serbo-Croatian Latin: Peta neprijateljska ofanziva) in Yugoslav historiography and often identified with its final phase, the Battle of the Sutjeska (Serbo-Croatian Latin: Bitka na Sutjesci pronounced [bîtka na sûtjɛst͡si]) was a joint attack by the Axis. Taking place from 15 May to 16 June 1943, it aimed to destroy the main Yugoslav Partisan force, near the Sutjeska River in south-eastern Bosnia. The failure of the offensive marked a turning point for Yugoslavia during World War II. It was also the last big German–Italian joint operation against the partisans.
The operation immediately followed Operation Weiss, which had failed to accomplish the same objectives, to eliminate the central Partisan formations and capture their commander, Josip Broz Tito.
Background
During the previous operation Weiss, Chetniks fought against Partisans under Italian command. However, even during the operation, negotiations were held between the German and Italian leaders on the disarmament of the Chetniks. Because of Allied deception, German Wehrmacht deeply believed that the Allies would invade the Balkans instead Sicily after victory in the North African campaign. In operations Weiss I and Weiss II, the Wehrmacht did not achieve their desired goals of destroying the Yugoslav partisans and establishing control over the region, so preparations began for a new venture.
With operation Schwarz, the Wehrmacht intended to clear the background of the Adriatic coast by destroying both the Chetnik and Partisan movements, which were still firmly established in Herzegovina and Montenegro. Hitler calculated that, in the event of a British invasion of the Balkans, Chetniks under Italian care would switch sides and join the Allies.
However, in the first phase, there were tensions and misunderstandings between the German and Italian armies on that issue. Since the Italian commanders in Yugoslavia were very reluctant to disarm the Chetniks, Hitler won the consent through Mussolini government and the Italian Supreme Command. General Mario Robotti was fiercely against the disarmament of the Chetniks, at least until the partisans were destroyed. This attitude was shared by Chief of Staff of the Italian Army, general Vittorio Ambrosio, but he had to obey the promise that Mussolini gave to Hitler. At the beginning of March 1943, general Ambrosio, summoned Robotti and Alessandro Pirzio Biroli to Rome for talks on the disarmament of Chetniks and operations against partisans.
Axis plans
The Axis rallied 127,000 land troops for the offensive, including German, Italian, Croatian, Bulgarian, and over 300 aeroplanes.
For this operation, the Commander of the Southeast, colonel-general Alexander Löhr, received elite 1st Mountain Division from the Eastern Front as reinforcements. Löhr entrusted the tactical command to the German troop commander in Croatia, Rudolf Lüters. The combat group for this operation was therefore called the Croatian Corps.
The German command adjusted the operational plan of action against the Partisans to the characteristics of the terrain. They planned to concentrate the main partisan divisions and their Supreme Headquarters on the naturally isolated and almost uninhabited area between the Tara and Piva canyons, and the Durmitor mountain, and to destroy it there with the mass use of aviation, artillery and mountain troops. The 1st Mountain Division with its northern wing, the Italian 19th Infantry (Mountain) Division Venezia, the battle group Ludwiger (724th German, 61st and 63rd Bulgarian Regiments), the 369th Infantry Division, the 118th Jäger Division with the 4th Home Guard Jäger Brigade of the Independent State of Croatia were deployed in a semicircle on the east and north sides. In the first phase, these forces were supposed to take control of Sandžak and push Partisan forces to the left side of the River Tara. The southern wing of the 1st Alpine Division Taurinense, 23rd Infantry Division Ferrara and the 7th SS Mountain Division Prinz Eugen were supposed to push Partisans from the south and southeast. After that, the 118th Jäger Division had the task of occupying the left bank of the Piva and thus closing the environment, so that the breakthrough was hindered not only by strong forces but also by deep river gorges. This would bring Partisan forces to a dead end and destroy them.
In addition to these forces, there were additional 4 Italian divisions deployed in Adriatic hinterland, from the Albanian border to the lower course of the Neretva: were these Italian divisions: 155th Infantry Division Emilia in the Bay of Kotor, 151st Infantry Division Perugia in area of Vilusi, Bileća and Trebinje, 154th Infantry Division Murge around Dubrovnik and 32nd Infantry Division Marche in
downstream of the Neretva, from Mostar to Metković.
Partisans' activities prior to Axis offensive
While the Axis were preparing for Operation Schwarz, fierce battles were fought on the territory of Herzegovina and Montenegro. After operation Weiss, the operative group of Partisan divisions set out with all its might through Herzegovina to break into Montenegro, destroying the Chetniks and Italians units on its path, and taking control over the area. In that area, the exhausted fighters would rest, the wounded would be treated, and then they would move towards Kosovo and southern Serbia.
Fierce battles between partisans and Italian-Chetnik forces were fought in the sector Foča-Kalinovik-Gacko-Šavnik. Nevesinje passed from hand to hand as many as eight times. On April 6, Partisan forces forced the Drina, defeated parts of the Taurinense division and the Chetniks near Ifsar, captured Čajniče and besieged Foča, where an Italian battalion and about 1,000 Chetniks were surrounded. Chasing the Chetniks deeper and deeper into Montenegro, the Supreme Headquarters moved to Mount Durmitor.
After the heavy defeat inflicted on the Italians in Pivka Javorka, on 1 May, the First and Second Proletarian Divisions embarked on a comprehensive offensive to liquidate the Italian-Chetnik garrison in Kolašin, with the intention of continuing the advance towards Berane. As part of the siege of Kolašin, a strike group of battalions (two battalions of the Fourth and one battalion of the Fifth Montenegrin Brigade) defeated the Italian regiment near Bioč on 15 May.
At the beginning of operation Schwarz, the Yugoslav National Liberation Army had 22,148 soldiers in 16 brigades. There were 8,925 Partisans from Croatia (5,195 of those from Dalmatia), 8,293 from Bosnia and Herzegovina, 1,492 from Serbia (including Vojvodina and Kosovo) and 3,337 from Montenegro. By ethnicity, 11,851 were Serbs, 5,220 Croats, 3,295 Montenegrins and 866 Muslims.
Partisan units were bringing with them a central hospital with about 3,000 wounded. In addition, YNLA troops suffered from severe lack of food and medical supplies, and many were struck down by typhoid.
Operation
Axis preparations
Wehrmacht forces were advancing towards Montenegro from the north and from the east. Partisan forces were keeping parts of the Italian Alpine Division "Taurinense" and about 1,100 Chetniks under blockade in Foča since 15 April. In early May, parts of the German 369th Legionary Division penetrated as far as Foča, suppressing the Sixth East Bosnian and Fifteenth Majevica Brigades, liberating the Aosta battalion of the Italian Taurinense division and about 1,000 Chetniks, who had been under siege by Partisan forces for 23 days. The Chetniks were disarmed and released.
The left wing of the 369th Legionary Division advanced from the direction of Priboj towards Pljevlja, and, without encountering any resistance, merged with the main body of the "Taurinense" division.
Disarmament of Chetniks
During the advance of the 7th SS Mountain Division and the 118th Jäger Division through eastern Herzegovina, German forces encountered a certain degree of Italian obstruction and skirmishes with the Chetniks. Hundreds of Chetniks were disarmed.
At the beginning of May, Pavle Đurišić established contacts with parts of the 1st Mountain Division and the 4th Brandenburg Regiment. The Germans decided to conceal their real intentions, so they let the first group of disarmed Chetniks go home. By accepting communication with the Chetniks, by mid-May 1943 they managed to concentrate a large number of Chetniks, led by Đurišić, around the town of Kolašin, where German combat units were already deployed. In a surprise raid on the morning of 14 May, despite the established contacts and strong opposition of the commander of the Italian 14th Corps, General Ercole Roncaglia, the Germans captured the Chetniks in their sleep and disarmed them. German forces on the ground appealed to the higher command to reconsider the decision to arrest the Chetniks, because they proved to be reliable allies against the partisans, but the German command did not give up on the original idea. One part of captured Chetniks, including Đurišić, was to be interned in prison camps in Greece and Poland, and the rest for labour battalionss in the upcoming fight against the Partisans. In the meantime, Mihailović left the village of Gornje Lipovo and headed for Serbia. After capturing the majority of Montenegrin Chetniks near Kolašin, the Germans continued with operation Schwarz.
Phase I: Initial battles (15–20 May)
After a period of troop concentration, the offensive started on 15 May 1943. The Axis troops used the advantage of better starting positions to encircle and isolate the partisans on the Durmitor mountain area, located between the Tara and Piva rivers in the mountainous areas of northern Montenegro and forced them to engage in a fierce month-long battle on waste territory.
The first clashes after Operation Schwarz commenced took place in the north, between Čajniče and Foča, with parts of the 369th Legionary Division, and in the east, near Brodarevo and Mojkovac, with the 1st Mountain Division.
Phase II: Breakthrough attempt toward eastern Bosnia (21–27 May)
Faced with the advance of large German forces from the east, the Supreme Headquarters decided to prevent the closure of the ring by capturing Foča and providing communication with eastern Bosnia. The attack was carried out from 21 May to 25 by the reinforced 1st Proletarian Division against the majority of the German 118th Jäger Division and the 4th Home Guard Jäger Brigade of the Independent State of Croatia. Despite certain tactical successes (breaking up of the 7th Mountain Regiment on 21 May and the 13th Mountain Regiment on 24 May), after a flanking attack by parts of the 369th Division near Gradac on 25 May, this attack proved hopeless. From there, on 27 May, the Supreme Headquarters ordered the transfer of all forces to the left bank of the Tara.
The 118th Jäger Division had the task of breaking out on Piva from the west and blocking it. On 22 May, her 738th Regiment, without contact with Partisan units, broke out on Vučevo, a plateau west of Piva. However, they could not organize communications and supplies in this wide and impassable area, so the regiment commander, lieutenant colonel Anacker, sent one battalion to the south to establish a connection with the 7th SS Division, and one to the west, to connect with the headquarters of his division. The remaining, 2nd Battalion, in a battle on 29 May, was repelled from dominant positions by the two battalions of the 2nd Proletarian Brigade. The intervention of parts of the division from the north, across the Drina, was suppressed by the forces of the 1st Proletarian Division, which moved across the Tara. Thus, the Partisan forces firmly occupied Vučevo and prevented the Germans from closing the ring on Piva. The next natural obstacle on which the 118th Division could do that was the valley of the river Sutjeska.
On 18 May, the 7th SS Division and the Italian Division Ferrara began to appear from the south towards Šavnik, Žabljak and Mratinje. The successful defence of the First Dalmatian and the Fifth Montenegrin Brigades, which suppressed the appearance of the right wing of the 7th SS Division and the Italians, enabled the organization of an attack on the left wing of the 7th SS Division.
Phase III: Arrival of British mission (27 May – 3 June)
Informed on 20 May 1943 of the arrival of the British military mission, the Supreme Headquarters left Đurđevića Tara and settled in the forest near Black Lake, at the foot of Durmitor.
On the night of 27/28 May, the British Liaison Department arrived. At the head of this mission were Captain William F. Stewart, who worked at the British Consulate in Zagreb before the war spoke Serbo-Croatian, and William Deakin, a history professor at Oxford. In addition to the two of them, the mission had 4 more members.