Case Black

In mid-May 1943, in the mountains of northern Montenegro and eastern Herzegovina, the largest Axis operation yet against the Yugoslav Partisans got under way. The German command gave it the code name Schwarz (“Black”), and it is known in English as Case Black. Some 120,000 German, Italian, Bulgarian and Croatian troops, supported by more than 300 aircraft, were to encircle and destroy the main forces of Josip Broz Tito, together with his Supreme Headquarters, his field hospital and the leaders of the Communist Party of Yugoslavia. At the same time the Germans wanted to disarm the Chetniks of Draža Mihailović, with whom the Italians had long been collaborating against the communists. In Yugoslav historiography the operation is known as the “Fifth Enemy Offensive” (Peta neprijateljska ofanziva), and its last phase, in June, as the Battle of the Sutjeska.

It is often recorded under 17 May that the Germans launched the fifth great offensive against Tito’s Partisans. The numbering of the offensives follows Yugoslav tradition, but the date needs correcting: according to German documents and Yugoslav studies the operation began on 15 May 1943, and the day before, 14 May, the Germans had surprised and disarmed the Chetniks assembled near Kolašin. By 17 May the advance was already under way on several axes.

After the Battle of the Neretva

Case Black was a direct continuation of Case White (Fall Weiss), which the Germans and Italians had conducted from January to March 1943 in western Bosnia, Lika and Dalmatia. Its aim had been to destroy the so-called Republic of Bihać, a large territory seized by the Partisans in the autumn of 1942. The operation had ended with the Battle of the Neretva: at the beginning of March Tito blew up the bridges over the river, deceived the enemy with a feigned retreat and then took his divisions and several thousand wounded across the Neretva on a makeshift footbridge. On the other side he routed the Chetniks who, under Italian command, had tried to bar his way. The Partisans broke out of the encirclement weakened but not destroyed.

In March 1943 the Partisan command held talks with the Germans on an exchange of prisoners and a temporary suspension of hostilities; on the Partisan side they were conducted by Milovan Đilas and Koča Popović. Tito wanted to gain time and deal with the Chetniks; the Germans wanted to secure the railway and the mines. Hitler, however, forbade further negotiations with “bandits”, and the talks produced nothing lasting. In April the Partisans crossed Herzegovina towards the Drina and Montenegro. Along the way they routed Chetnik and Italian units and for more than three weeks besieged Foča, which held an Italian battalion and about a thousand Chetniks, while the Supreme Headquarters moved to the area of the Durmitor massif. In Montenegro, a country that had risen against the Italians as early as July 1941, Tito hoped to rest, treat his wounded and continue his march towards the Sandžak, Kosovo and southern Serbia.

Fear of a landing in the Balkans

Behind the new operation lay, above all, Hitler’s fear for the hinterland of the Adriatic coast. In the spring of 1943 the fate of the Tunisian campaign was being decided in North Africa, and on 13 May the remnants of the Axis forces surrendered in Tunisia. It was clear to Berlin that the Allies would soon strike somewhere in southern Europe. The British deception Operation Mincemeat and other intelligence ploys confirmed the Germans in their belief that the target might be Greece and the Balkans. In the event of a landing, the Yugoslav mountains, full of armed bands, would become a mortal threat to German supply lines, to the bauxite, copper and chrome mines, and to the railway to Salonika and Athens.

The Germans trusted neither the Partisans nor the Chetniks. Mihailović’s movement was loyal to King Peter II and the government-in-exile in London, and in the event of an Allied landing – so Berlin reasoned – it would turn its arms against the Axis. Meanwhile, since 1942 the Italians had been arming and supplying Chetnik units in Montenegro, Herzegovina and Dalmatia, treating them as cheap help in the fight against the communists. The dispute over the Chetniks had dragged on since the winter; it came up again at the meeting between Hitler and Mussolini at Klessheim in April 1943, but remained unresolved there. Only in the following weeks, under pressure from Berlin, did Benito Mussolini agree to the disarming of the Chetniks. The Italian commanders on the spot – General Alessandro Pirzio Biroli, governor of Montenegro, and General Mario Robotti, commander of the Second Army – as well as the Chief of the Italian General Staff, General Vittorio Ambrosio, wanted to disarm the Chetniks only after the Partisans had been crushed, but they had to bow to the Duce’s promise.

By the spring of 1943 Yugoslavia had not existed as a state for two years. After its capitulation in April 1941 the country had been partitioned by Germany, Italy, Hungary and Bulgaria, and in the middle the Ustaše Independent State of Croatia of Ante Pavelić had been created, which also took in Bosnia and Herzegovina. Montenegro remained under Italian occupation. The Partisans and the Chetniks, who in the autumn of 1941 had entered into open war with each other, fought in these mountains not only against the occupiers but also against one another – and the civilian population paid a terrible price for it.

Plan and forces

The operation as a whole was directed by Colonel General Alexander Löhr, an Austrian, formerly commander of Luftflotte 4 and since the beginning of 1943 commander of Army Group E and of the Wehrmacht in the south-east. He entrusted tactical command to General Rudolf Lüters, commander of German troops in Croatia; the battle group was called the Croatia Corps. The elite 1st Mountain Division was brought in from the Eastern Front. Alongside it operated SS-Gruppenführer Artur Phleps’s 7th SS Volunteer Mountain Division Prinz Eugen, made up mainly of Banat Germans, the 104th and 118th Jäger Divisions, the 369th Infantry Division (the “Devil’s Division”, with Croatian soldiers and German officers), the Brandenburg Regiment, the Bulgarian 61st and 63rd Regiments and the Croatian 4th Mountain Brigade of the Home Guard (Domobrani). The Italians fielded the Taurinense, Venezia and Ferrara divisions, while four more guarded the coastal strip from the Albanian border to the lower Neretva.

The plan made use of the terrain. The Axis forces were to deploy in a semicircle from the north, east and south, push the Partisans out of the Sandžak across the river Tara and squeeze them into an almost uninhabited pocket between the canyons of the Tara and the Piva and the Durmitor massif. The 118th Jäger Division was then to occupy the left bank of the Piva and close the ring from the west, so that the escape route would be cut not only by troops but also by gorges hundreds of metres deep. In this closed sack, aircraft, artillery and mountain troops were to destroy the Partisans to the last man.

The figures given by historians differ depending on whether they include the units guarding the coast and lines of communication. The most commonly cited figure for the Axis forces, taken from Yugoslav historiography, is some 127,000 men and more than 300 aircraft. Not all of these forces fought directly in the pocket – some were guarding roads, railways and the coast. Tito’s operational group numbered, according to the same sources, about 22,000 men in 16 brigades: the 1st and 2nd Proletarian Divisions (commanded by Koča Popović and Peko Dapčević), the 3rd Assault Division, the 7th Banija Division and several independent brigades. The Partisans had small arms, some mortars and a few captured guns, but no aircraft, no communications with the outside world and no food stocks. They dragged with them the Central Hospital – several thousand wounded and sick, among whom typhus was spreading. Members of the party’s Central Committee and some of the delegates of AVNOJ, the Partisan parliament set up at Bihać in November 1942, marched with the Supreme Headquarters.

The Chetniks first

The first blow fell on the Chetniks. At the beginning of May the German 369th Division fought its way through to Foča, relieved the Italian battalion besieged there and disarmed about a thousand Chetniks who had been defending the town together with the Italians. The commander of the Montenegrin Chetniks, Pavle Đurišić, made contact with the 1st Mountain Division and the Brandenburg Regiment, hoping for joint action against the communists. The Germans allowed his men to assemble around Kolašin, and on the morning of 14 May they surrounded and disarmed them, despite the protests of the Italian commander of XIV Corps, General Ercole Roncaglia. Some German officers on the spot asked their superiors to change the order, since the Chetniks had proved useful allies against the Partisans, but the high command did not give way. Đurišić was taken to a prisoner-of-war camp in Galicia, from which he escaped in the autumn, and some of his men were sent to labour battalions. Mihailović, who had been staying in Montenegro since the spring, in the village of Gornje Lipovo near Kolašin, left the threatened area in those days and returned to Serbia. His movement in Montenegro and Herzegovina, built up under an Italian umbrella, had suffered a heavy blow – and not at the hands of the Partisans, but of the Germans.

The first days of the offensive

The advance began on 15 May. The first clashes took place in the north, between Čajniče and Foča, where the Partisans ran into the 369th Division, and in the east, near Brodarevo and Mojkovac, where the 1st Mountain Division was attacking. On 18 May the SS division Prinz Eugen and the Italian Ferrara appeared from the south, advancing on Šavnik, Žabljak and Mratinje. The Supreme Headquarters quickly realised that this was not just another anti-partisan sweep but a large-scale encirclement. The Dalmatian and Montenegrin brigades held up the right wing of the SS division and the Italians, but the ring was tightening on all sides.

Tito decided to forestall the closing of the encirclement and break out to the north, through Foča into eastern Bosnia. From 21 to 25 May the reinforced 1st Proletarian Division attacked the 118th Jäger Division and the Croatian mountain brigade. On 21 and 24 May the Partisans routed two enemy regiments, but on 25 May a flank attack by the 369th Division near Gradac destroyed their chances of success. On 27 May the Supreme Headquarters ordered all forces to cross to the left bank of the Tara. Meanwhile, on 22 May, the German 738th Regiment of the 118th Division had come out onto the Vučevo plateau, west of the Piva, to close the ring from the west. The regiment, however, was unable to organise its supply in the trackless terrain and dispersed its forces, and on 29 May two battalions of the 2nd Proletarian Brigade drove it from its key positions. Vučevo remained in Tito’s hands – and it was through it that the only road to the Sutjeska would lead in June.

The British in the pocket

In the very middle of the offensive the first British officers arrived at the Supreme Headquarters. Until the spring of 1943 London had recognised and supported only Mihailović, the War Minister of the government-in-exile, and knew of Tito’s Partisans mainly from intercepted German signals, read thanks to the breaking of the ciphers. It was these signals that convinced some officers at the Cairo headquarters of the Special Operations Executive that the communists were bearing the main burden of the fight against the Germans in Yugoslavia. In April a group of Canadian emigrants of Yugoslav origin had been dropped to the Partisans in Croatia as a trial. On 20 May the Supreme Headquarters learned that a liaison mission was flying in to it, and moved to the woods by the Black Lake at the foot of Durmitor.

On the night of 27–28 May 1943 six men of a mission code-named Typical parachuted onto Durmitor. It was led by Captain William F. Stuart, before the war an employee of the British consulate in Zagreb, who spoke Serbo-Croat, and Captain William Deakin, a young Oxford historian who before the war had assisted Winston Churchill with his biography of the Duke of Marlborough. On 28 May Tito received the British. He asked for weapons, medicines and the bombing of German concentrations. From the very first days Deakin shared the marches, the hunger and the air raids with the Partisans, and his reports, sent over the mission’s radio, gave London for the first time a close-up picture of the Partisans’ fighting.

Place in the war

At the end of May Case Black was only entering its hardest phase. At the beginning of June Tito and the Supreme Headquarters crossed the Piva near Mratinje and found themselves, together with the Central Hospital, inside the tightening ring. The headquarters divided its forces: the 1st and 2nd Proletarian Divisions were to break out to the north-west, through the valley of the Sutjeska and the Zelengora massif, while the 3rd and 7th Divisions with the wounded were to turn back east towards the Sandžak. On 9 June, at Milinklade, a German aerial bomb wounded Tito in the arm and killed Captain Stuart. On 13 June the commander of the 3rd Division, Colonel Sava Kovačević, was killed in an attack on the Sutjeska. Nevertheless the main forces broke through the lines of the German 118th and 104th Jäger Divisions and the 369th Division and by mid-June had reached eastern Bosnia. By 16 June the operation was over.

The price was enormous. According to Yugoslav historiography the Partisans lost between about 6,400 and more than 7,500 killed, roughly a third of their strength. Many of them did not die in battle: in accordance with Hitler’s orders, Löhr ordered all those captured to be destroyed, including the wounded and unarmed medical staff. A report by the 1st Mountain Division recorded 498 prisoners, of whom 411 were shot. The Germans used dogs to search out the seriously wounded hidden in the forests and killed them along with their nurses. Civilians suspected of sympathising with the Partisans were also among the victims; the Yugoslav chronicle of the fighting gives a figure of more than 2,500 shot. In General Lüters’s report of 20 June the Germans listed 583 killed, 1,760 wounded and 425 missing. The same report admitted that the “communist rebels” were well organised, skilfully led and had incredibly high morale.

Case Black destroyed neither Tito nor his army. The Partisans quickly made good their losses with new volunteers and within a few weeks had overrun German and Croatian garrisons in eastern Bosnia. The Chetnik movement in Montenegro and Herzegovina, by contrast, had been broken, and Mihailović had lost the base that the Italians had provided for him for two years. The reports of Deakin and, from September 1943, of Brigadier Fitzroy Maclean, Churchill’s personal envoy, convinced London that it was the Partisans who were really fighting the Germans. After Italy’s capitulation in September 1943 Tito took over the weapons of several Italian divisions, and at the end of the year the Allies at Tehran agreed to support his army. In 1944 the British withdrew their missions from Mihailović. The Battle of the Sutjeska became one of the founding myths of post-war Yugoslavia; in 1973 it was the subject of the film Sutjeska, with Richard Burton as Tito. After the war Löhr was sentenced to death for war crimes by a Yugoslav military court and executed in Belgrade in February 1947.