On 6 April the ELI Corps crossed the Yugoslav border at Murk and Radkersburg and seized both bridges across the Drava intact. During these probing attacks the 132d Infantry Division occupied the Sejanska stream and the 183d Infantry Division took 300 prisoners. A bicycle detachment of the latter entered Murska Sobota without encountering resistance. Since the Yugoslavs were giving ground all along the line, the corps wanted to exploit the situation. The Second Army, however, felt compelled to order both divisions to hold in place and consolidate their newly won bridgeheads. The two divisions would have to wait until their remaining elements had detrained in the assembly areas.
During the following three days the LI Corps expanded its bridgeheads, the 132d Infantry Division occupying Maribor and the 183d probing beyond Murska Sobota. Air reconnaissance reports indicated that the Yugoslav Seventh Army forces employed in this sector were withdrawing southward along the narrow mountain roads leading to Zagreb. Apparently only a thin security screen had been left in place to maintain contact with the German forces in the bridgeheads.
The Second Army thereupon ordered LI Corps to form flying columns composed of motorized elements and pursue the retreating Yugoslav forces in the direction of Zagreb. On 10 April cold winds and intermittent snowstorms hampered the movements of the advancing Germans, and flood waters interrupted the crossings at Maribor during the day. After regrouping its forces south of the Drava the LI Corps resumed its advance toward Zagreb at 0600 on 11 April. Plodding through difficult terrain during the afternoon, forward elements reached the southern exit of the mountain range northwest of the city by evening. A bicycle troop of the 183d Division wheeling eastward had, meanwhile, taken Varazdin, where it captured a Serb brigade, including its commanding general.
XLIX Mountain Corps
On 6 April, while the 1st Mountain Division was still on the approach march, the 538th Frontier Guard Division, stationed along the northwestern part of the Slovenian border, succeeded in seizing important mountain passes, hills, and tunnels in Yugoslav territory. During the night of 9-10 April the combat elements of the 1st Mountain Division, which had detrained only a few hours earlier, began to cross the frontier near Bleiburg. Advancing in the general direction of Celje the division spearheads stood about twelve miles northwest of the town by nightfall. After exhausting marches and some hard fighting the 1st Mountain Division took Celje on 11 April. Emissaries of the newly formed Slovenian Government asked the corps commander for a cease-fire. In anticipation of just such developments, Hitler had previously authorized field commanders to accept the surrender of individual units.
14th Panzer Division (XLVI Panzer Corps)
Early on the morning of 10 April, with dive-bombers clearing the route of advance, the 14th Panzer Division of XLVI Panzer Corps, split into two armored forces, broke out of the Drava bridgehead and advanced southwestward toward Zagreb, the state capital of Croatia. This attack preceded the XLVI Panzer Corps main attack toward Belgrade and was intended as a diversion.
Although large enemy concentrations had been spotted in front of the division, air reconnaissance revealed that these forces were rapidly withdrawing westward toward Zagreb. Though fierce at first, enemy resistance soon crumbled as German tanks came closer to their objective. However, extremely cold weather and snow-covered roads hampered progress to some degree. By 1930 on 10 April the lead tanks of the 14th Panzer Division reached the outskirts of Zagreb, after having covered a distance of almost 100 miles in one day.
In some instances Croat troops refused to fight, abandoned their weapons, deserted their positions, and either surrendered or simply went home. One German regiment surprised an enemy unit which was still in garrison and not yet fully mobilized. A regimental officers’ party just in progress was interrupted only long enough to consummate a quick surrender, whereupon the festivities continued as though nothing unusual had happened.
So rapid was the advance of the division that its radio communications with corps and army were temporarily interrupted. Reconnaissance aircraft had to be dispatched to ascertain its exact location and chart its progress. When the 14th Panzer Division entered Zagreb from the northeast it was welcomed by a wildly cheering pro-German populace. During the drive on the city more than 15,000 prisoners were taken. Among the 300 officers were twenty-two generals, including the commanders of First Army Group and Seventh Army.
On 11 April the newly formed Croatian Government called on its nationals to cease fighting and requested that they be immediately released by the Yugoslav Army. During the evening hours the first LI Corps elements entered Zagreb from the north and relieved the 14th Panzer Division.
Italian and Hungarian Operations
The favorable course of the military events along its front led the German Second Army to offer its assistance to the Italian Second Army assembling along Yugoslavia’s western border. On the early morning of 11 April the Germans were informed that the Italian V, VI, and XI Corps would be ready to attack toward 1200. To speed up the Italian advance and consummate the encirclement of the Yugoslav Seventh Army forces in the Ljubljana Basin, the German XLIX Mountain Corps was to conduct the diversionary attacks in the north while 14th Panzer Division forces were to cut the enemy’s route of withdrawal. As a preparatory step the German Fourth Air Force attacked Yugoslav columns and troop concentrations in the Ljubljana area. When the Italian forces finally jumped off, they encountered little resistance from the Yugoslavs, who were attempting to withdraw southeastward. A great number of prisoners and much booty were captured as entire divisions surrendered. About 30,000 Yugoslav troops concentrated near Delnice were waiting to surrender to the Italians who were moving southeastward in the direction of the Dalmatian coast.
On 12 April elements of the 14th Panzer Division linked up with the Italians at Vrbovsk. The line Novo Mesto-Slunj-Bihac-Livno was designated as the boundary between the German and Italian Second Armies south of the Sava. Occupation of the territory west of this line was assigned to the Italians. However, for the time being the German units on the extreme right wing of XLIX Mountain Corps were authorized to operate in the Italian zone.
Upon moving its command post to Maribor on 11 April, the German Second Army headquarters received a message from the Hungarian Third Army by which it was notified that Hungarian troops were crossing the Yugoslav frontier north of Osijek and near Subotica. On the next day the Hungarians pursued the retreating Yugoslav First Army and occupied the area between the Danube and Tisza Rivers, meeting virtually no resistance.
The Final Drive on Sarajevo
After the collapse of the border defense system and the fall of Belgrade the Yugoslav Army leaders had hoped to withdraw to the mountain redoubt in the interior of Serbia, where they intended to offer prolonged resistance. Fully aware of the Yugoslav intentions, General von Weichs, the Second Army commander, decided to launch and maintain a vigorous pursuit of the enemy forces withdrawing in the general direction of Sarajevo. Speed was now of the essence since the German Army High Command intended to pull out and redeploy as soon as practicable the motorized and armored divisions that had to be refitted for the Russian campaign.
As early as 12 April both the XLIX and LI Corps had closed up and regrouped their forces along the Sava River. Sarajevo, located in the heart of Yugoslavia, was to be the focal point upon which the German forces were to converge. Accordingly, Second Army reorganized its forces into two separate pursuit groups. Under the command of the recently arrived LII Infantry Corps headquarters, the western group consisted of four infantry divisions under the XLIX and LI Corps as well as the 14th Panzer Division, the formation that was to spearhead the drive on Sarajevo from the west. The eastern pursuit force, under the command of the First Panzer Group, was composed of six divisions, with the 8th Panzer Division leading the drive toward Sarajevo from the east. The Fourth Air Force, continuing to operate in support of the ground operations, was ordered to neutralize the anticipated enemy troop concentrations in the Mostar-Sarajevo sector.
On the afternoon of 13 April Second Army moved its command post to Zagreb to facilitate communication with the two pursuit groups and direct the mopping-up phase of the campaign from this central location. The boundary between the German Second and Twelfth Armies was the line extending laterally across Yugoslavia from Sofiya via Prizren up to and along the northern border of Albania.
By the evening of 13 April there was no longer any semblance of enemy resistance in front of XLIX and LI Corps. The main body of the German forces reached the Kupa River and some elements were quickly put across. The 14th Panzer Division, meanwhile, sped southeastward toward Sarajevo. As the division approached its objective, reports began to circulate that open hostilities had broken out between Serbs and Croats in Mostar. German planes were quickly diverted to this area where they blasted Serb troop concentrations for three hours. By 14 April the fighting between the Serb and Croat factions had gained momentum and had spread throughout Dalmatia. On that day the 14th Panzer Division reached Jajce, approximately fifty miles northwest of Sarajevo, while forward elements of the LI Corps, attempting to keep up with the armor, arrived at the Una after strenuous marches and established several bridgeheads across the stream.
In the zone of the eastern group, one armored division combed out the sector south of Belgrade, while two infantry divisions cleared the industrial region in and around Nis. The 8th Panzer Division led the way southwestward toward Sarajevo, closely followed by two motorized infantry divisions which were driving hard toward the heart of Yugoslavia, one via Zvornik, the other from Uzice. Among the vast amount of booty were seventy-five enemy aircraft still intact on the ground. During the operations on 14 and 15 April, prisoners were taken by the thousands. North of Nis the Germans captured 7,000; in and around Uzice, 40,000; around Zvornik 30,000 more; and in Doboj another 6,000.
On 15 April both pursuit groups of Second Army closed in on Sarajevo. As two panzer divisions entered the city simultaneously from. west and east, the Yugoslav Second Army, whose headquarters was in Sarajevo, capitulated. Leaving only security detachments in the city to await the arrival of the infantry forces, both divisions continued to race southward in close pursuit of fleeing enemy remnants.
In view of the hopelessness of the situation, the Yugoslav command decided to ask for an armistice and authorized the commanders of the various army groups and armies to dispatch truce negotiators to the German command post within their respective sectors. However, those from Yugoslav Second and Fifth Armies who asked for separate cease-fire agreements on 14 April were turned back by the German commanders because by that time only the unconditional surrender of the entire Yugoslav Army could be considered as a basis for negotiations.
Late on the evening of 14 April, a representative of the Yugoslav Government approached the First Panzer Group headquarters and asked General van Kleist for an immediate cease-fire. When the Army High Command was advised of this turn of events, it designated the Second Army commander, General von Weichs, to conduct the negotiations in Belgrade.
During the afternoon of the following day von Weichs and his staff arrived in Belgrade and drew up the German conditions for an armistice based on the unconditional surrender of all Yugoslav forces. The next day a Yugoslav emissary arrived in the capital, but it turned out that he did not have sufficient authority to negotiate or sign the surrender. Therefore, a draft of the agreement was handed to him with the request that competent plenipotentiaries be sent to Belgrade without delay in order to avoid unnecessary bloodshed. To expedite matters, a plane was placed at his disposal.
The armistice was concluded and signed on 17 April. (General von Weichs signed for the Germans, with the Italian military attaché in Belgrade acting on behalf of his country. The Hungarians were represented by a liaison officer who, however, did not sign the document since Hungary was technically “not at war with Yugoslavia.” Foreign Minister Cincar-Marcovic and General Milojko Yankovic signed for the Yugoslavs. The armistice became effective at 1200 on 18 April 1941, just twelve days after the initial German attack was launched.
The losses sustained by the German attack forces were unexpectedly light. During the twelve days of combat the total casualty figures came to 558 men: 151 were listed as killed, 392 as wounded, and 15 as missing in action. During the XLI Panzer Corps drive on Bel grade, for example, the only officer killed in action fell victim to a civilian sniper’s bullet.
The Germans took some 254,000 prisoners, excluding a considerable number of Croat, German, Hungarian, and Bulgarian nationals who had been inducted into the Yugoslav Army and who were quickly released after screening.