The 2nd Army Group was a Royal Yugoslav Army formation commanded by Armijski đeneral Milutin Nedić during the German-led Axis invasion of the Kingdom of Yugoslavia in April 1941 during World War II. It consisted of the 1st and 2nd Armies, comprising four infantry divisions, one horsed cavalry division, one horsed cavalry regiment, and two brigade-strength infantry detachments. It was responsible for the defence of the border with Hungary from Slatina to the Tisza river.
The 2nd Army Group was not directly attacked during the first few days of the invasion, but events to the east and west of its deployment area resulted in successive orders to withdraw to the lines of the Drava and Danube then the Sava. On 10 April, the crumbling defences of the 4th Army on the left flank of the 1st Army Group had been penetrated by the German 8th Panzer Division, which then turned east and drove into the left flank of the 1st Army Group on the following day. By the end of that day, the Germans had effectively routed the 2nd Army Group. Remnants continued to fight along the line of the Sava until early on 14 April, but mass surrenders began that day with tens of thousands of Yugoslav soldiers being taken into captivity by the Germans during their drive on Sarajevo in the centre of the country. The Yugoslav High Command unconditionally surrendered in Belgrade effective at 12:00 on 18 April.
The 2nd Army Group was commanded by Armijski đeneral Milutin Nedić, and consisted of the 1st Army, commanded by Armijski đeneral Milan Rađenković, and the 2nd Army, commanded by Armijski đeneral Dragoslav Miljković. The 1st Army consisted of one infantry division, one horsed cavalry division, and two brigade-strength infantry detachments, and was supported by artillery, anti-aircraft artillery, and air reconnaissance elements of the Royal Yugoslav Air Force. The 2nd Army consisted of three infantry divisions and one horsed cavalry regiment, supported by artillery, anti-aircraft artillery and border guards, with air reconnaissance support. The 2nd Army Group did not control any additional support units, and had several units with a significant proportion of Croat soldiers.
The deployment plan for 2nd Army Group saw the 1st Army in the Bačka region between the Danube and the Tisza, with formations centred around the towns of Sombor, Bačka Topola and Senta, with the 3rd Cavalry Division held in depth, south of the Danube in the Fruška Gora region. The 2nd Army deployment plan saw it in the Baranya and Slavonia regions between Slatina and the Danube, with its formations positioned south of the Drava from just east of Slatina to Valpovo, and around the towns of Osijek and Vinkovci. Of the formations of the 2nd Army Group, two infantry divisions of the 2nd Army were partly mobilised, while the remaining two infantry divisions, the 3rd Cavalry Division, and the two brigade-strength infantry detachments had only commenced mobilisation. To the right of the 1st Army Group was the 6th Army, an independent formation that was responsible for the defence of the Yugoslav Banat region east of the Tisza. The boundary with the 6th Army ran just to the east of the Tisza to the confluence with the Danube, then south across the Sava through Obrenovac. On the left flank of the 2nd Army Group was the 1st Army Group, which was responsible for the defence of northwestern Yugoslavia, along the Yugoslav–Hungarian west of Slatina, Yugoslav–Reich and Yugoslav–Italian borders. The army group boundary ran from just east of Slatina through Požega towards Banja Luka.
The 2nd Army Group faced the Hungarian 3rd Army across the border, and during the first few days after the commencement of the invasion, there were exchanges of fire with Hungarian border guards, but the Yugoslavs faced no direct attacks along the 2nd Army Group sector. Neither the 1st Army Group nor the Hungarians were ready for full-scale fighting, as they were still mobilising and deploying their forces. On 9 April, due to German successes elsewhere in Yugoslavia, the 6th Army on the right flank of the 2nd Army Group was ordered to withdraw south of the Danube and deploy on a line facing east to defend against an attack from the direction of Sofia, Bulgaria. 2nd Army Group also received orders to withdraw south of the line of the Drava and Danube. 1st Army began to withdraw, and on the same day elements were approaching the Danube crossing. The headquarters of the 2nd Army issued orders to evacuate Baranja and reinforce the left flank.
The following day, the situation deteriorated significantly when the German XLI Motorised Corps crossed the Yugoslav–Romanian border into the Yugoslav Banat and struck the 6th Army, halting its withdrawal and disrupting its ability to organise a coherent defence behind the Danube. Also on 10 April, the main thrust of the XLVI Motorised Corps of the 2nd Army, consisting of the 8th Panzer Division leading the 16th Motorised Infantry Division, crossed the Drava at Barcs in the 4th Army sector. The 8th Panzer Division turned southeast between the Drava and Sava rivers, and meeting almost no resistance and with strong air support, reached the left flank of the 2nd Army at Slatina by evening, despite poor roads and bad weather.
Later that day, as the situation was becoming increasingly desperate throughout the country, Dušan Simović, who was both the Prime Minister and Yugoslav Chief of the General Staff, broadcast the following message:
All troops must engage the enemy wherever encountered and with every means at their disposal. Don't wait for direct orders from above, but act on your own and be guided by your judgement, initiative, and conscience.
The bulk of the 1st Army were able to cross the Danube and began to prepare defences, and the 2nd Army was able to evacuate Baranja and organise a defence of the left flank of the 2nd Army Group, now threatened by the 8th Panzer Division, but Croat reservists began to desert their units, significantly reducing the combat power of the 2nd Army. By the evening of 10 April, the 2nd Army Group was ordered to withdraw from these positions and form a defensive line behind the Sava from Debrc to the confluence with the Vrbas river, for which one or two days would be needed. On the night of 10/11 April, the whole 2nd Army Group continued its withdrawal, but units of the 2nd Army on the left flank of the 1st Army that included significant numbers of Croats began to dissolve due to the fifth column activities of the fascist Ustaše and their sympathisers.
At dawn on 11 April, Hungarian forces, consisting with the Mobile, IV and V Corps of Altábornagy (Lieutenant General) Elemér Gorondy-Novák's 3rd Army, crossed the Yugoslav border north of Osijek and near Subotica, overcame Yugoslav border guards and advanced on Subotica and Palić. The XLVI Motorised Corps continued to push east south of the Drava, with the 8th Panzer Division capturing Našice, Osijek on the Drava, and Vukovar on the Danube, followed by the 16th Motorised Infantry Division which advanced east of Našice, despite bridge demolitions and poor roads. The 8th Panzer Division had effectively routed the 2nd Army Group by 11 April. On the same day, Messerschmitt Bf 110s of I Group of the 26th Heavy Fighter Wing (German: Zerstörergeschwader 26, ZG 26) destroyed several 1st Air Reconnaissance Group Breguet 19s at Ruma. The rest were flown to Bijeljina, but all of the air reconnaissance assets of the 2nd Army Group were destroyed the following day when I/ZG 26 swept over the airfield in one of the most effective attacks of the campaign. On the night of 11/12 April, the 8th Panzer Division captured Sremska Mitrovica on the Sava at 02:30, destroyed a bridge over the Danube at Bogojevo, and advanced on Lazarevac about 20 32 kilometres (20 mi) south of Belgrade. These advances delayed the withdrawal of the 2nd Army Group south of the Sava.
By 12 April, the withdrawal of the 2nd Army Group was being threatened from the left flank, and by this time, according to the Polish historian Andrzej Krzak, 2nd Army had "no combat importance at all". On the right flank, 6th Army attempted to regroup while being pressed by the 11th Panzer Division as it drove towards Belgrade. West of Belgrade, remnants of the 2nd Army Group tried to establish a line along the Sava, but XLVI Motorised Corps had already captured the bridges. When elements of the 8th Panzer Division captured Zemun without a fight, they captured 1st Army's rear area units. On 12 April, the 1st Army's 3rd Cavalry Division counter-attacked at Šabac and pushed the Germans back across the Sava. The Hungarians pursued the 1st Army south, and occupied the area between the Danube and the Tisza meeting virtually no resistance. Serb Chetnik irregulars fought isolated engagements, and the Hungarian General Staff considered irregular resistance forces to be their only significant opposition. The Hungarian 1st Parachute Battalion captured canal bridges at Vrbas and Srbobran. This, the first airborne operation in Hungarian history, was not without incident. The battalion's aircraft consisted of five Italian-made Savoia-Marchetti SM.75 transport aircraft formerly belonging to the civilian airline MALERT, but pressed into service with the Royal Hungarian Air Force (Hungarian: Magyar Királyi Honvéd Légierő, MKHL) at the start of the European war. Shortly after takeoff from the airport at Veszprém-Jutas on the afternoon of 12 April, the command plane, code E-101, crashed with the loss of 20 or 23 lives, including 19 paratroopers. This was the heaviest single loss suffered by the Hungarians during the Yugoslav campaign. Meanwhile, Sombor was captured against determined Chetnik resistance, and Subotica was also captured.
On the evening of 12 April, elements of the SS Motorised Infantry Division Reich, under command of XLI Motorised Corps, crossed the Danube in pneumatic boats and captured Belgrade without resistance. About the same time, most of the elements of XLVI Motorised Corps that were approaching Belgrade from the west were redirected away from the capital, but part of the 8th Panzer Division continued their thrust to capture the Sava bridges to the west of Belgrade, and entered the city during the night. The rest of the 8th Panzer Division turned southeast and drove towards Valjevo to link up with the left flank of the First Panzer Group southwest of Belgrade. The 16th Motorised Infantry Division was redirected south across the Sava, and advanced toward Zvornik.
On 13 April, the Hungarians occupied Baranja without resistance, and pushed south through Bačka to reach the line of Novi Sad and the Great Bačka Canal. Early on 14 April, the remnants of 2nd Army Group continued to fight against the 8th Panzer Division and 16th Motorised Infantry Division along the Sava. On 14 and 15 April, tens of thousands of Yugoslav soldiers were taken prisoner by the Germans during their drive on Sarajevo in the centre of the country, including 30,000 around Zvornik and 6,000 around Doboj. On 15 April, the 8th and 14th Panzer Divisions entered Sarajevo. After a delay in locating appropriate signatories for the surrender document, the Yugoslav High Command unconditionally surrendered in Belgrade effective at 12:00 on 18 April.