WW2 Campaign in Yugoslavia
A rugged, mountainous terrain and wide-meshed, underdeveloped road and rail networks were Yugoslavia’s strongest potential defensive assets. Although these assets were to be important during the years of guerrilla warfare, they did not serve to improve the country’s very difficult strategic position in April 1941. To defend a land frontier of 1,700 miles the Yugoslav Army had a hypothetical maximum strength of 1,000,000. Even if it had been able to call up that many men, it could not have armed and equipped them. Since 1939 the army had been cut off from its principal supplier of weapons and ammunition, the Skoda works in Czechoslovakia. Nevertheless, the General Staff proposed to employ eight of its nine armies, which at full strength were approximately equivalent to German corps, in a linear defense of the entire frontier. In the first week of April, it rejected a Greek plan to sacrifice most of the country for the sake of securing a strong common front with the Greeks and the British in the south. Moreover, no matter what the staff intended, deep-seated differences between the Serbian and Croatian elements in the population threatened to divide both the army and the nation as soon as war broke out.
When Gen. (later Field Marshal) Sir John Greer Dill, the British chief of staff, visited Belgrade on April 1, he found the government confused and almost apathetic. It seemed above all to wish to avoid provoking the Germans in the forlorn hope that a conflict could still be avoided or at least postponed. In the end, the only cooperation arranged between the Yugoslav and Greek forces took the quixotic form of a projected joint offensive against the Italians in Albania.
For the Germans the operation against Yugoslavia, in full swing 10 days after it was first ordered, was mainly an exercise in staff virtuosity. The most difficult task was to shift the German Second Army, composed of nine divisions under Col. Gen. (later Field Marshal) Maximilian von Weichs, to the northern Yugoslav border. The divisions had to be moved by rail and truck from France, Germany, and the Soviet border. The other major attack force, consisting of the five divisions of the 1st Panzer Group under Col. Gen. (later Field Marshal) Ewald von Kleist, was diverted from the assembly for the attack on Greece.
The plan was for the Second Army to break through the Yugoslav lines on a broad front north and northeast of Zagreb and to advance southward between the Drava and Sava rivers toward Belgrade. The 1st Panzer Group was to cross the border northwest of Sofia ( Sofiya), Bulgaria, take Nis, and thrust northward up the Morava Valley to Belgrade. A third force, the 41st Panzer Corps, taking the short route across the Rumanian border from the area south of Timi5oara, was to converge on Belgrade from the northeast.
In the early morning hours of April 6, German planes bombed Belgrade. They came in at rooftop level, and in an hour and a half killed more than 17,000 of the city’s inhabitants and almost completely destroyed the Yugoslav High Command’s communications with its forces in the field. The 1st Panzer Group crossed the border at daylight on April 8. While it encountered the Yugoslav Fifth Army, one of the few fully mobilized Yugoslav units, rough terrain and roadblocks proved to be the chief obstacles to its advance. After taking Nil on April 9, it broke away rapidly to the north toward Belgrade. In the meantime, another German force cut across southern Yugoslavia to divide the country from Greece. The Yugoslavs had opened their Albanian offensive on April 7, and for three days they made steady progress against the Italians.
The German Second Army launched local attacks on April 6, but because some of its major elements were still on the way, it did not attack in full strength until April 10. On that day, the Croat troops in the Yugoslav Fourth and Seventh armies, stationed on the northern frontier, mutinied, and by nightfall both armies had been dissolved. On the afternoon of April 10, Second Army troops entered Zagreb, where a newly created Croat government welcomed them as liberators. During the day, conceding by implication that he had lost control of the situation, General Simovic called on all Yugoslav units to engage the enemy “wherever they met him and by any means” without waiting for orders from higher headquarters.
German forces converged on Belgrade from three directions on April 12. In the early evening an SS lieutenant from the 41st Panzer Corps took a patrol into the capital, hoisted the swastika flag over the German legation, and accepted the mayor’s offer to surrender the city. On the morning of the following day, Easter Sunday, German armored spearheads entered Belgrade. The chief of the German Army General Staff noted in his diary that the campaign was over: all that remained was the mopping up. The Second Army had three columns moving westward and southwestward toward Sarajevo to block any attempt to establish a front in the mountains, but it encountered only masses of troops waiting to surrender. In some places fighting had broken out between Croat and Serb units.
On April 14, Gen. Danilo Katafatovic took command of the Yugoslav forces and opened negotiations for an armistice, which was signed three days later. German casualties in the campaign totaled 558; those of the Yugoslavs ran much higher. The Germans took 344,000 prisoners. The Yugoslav Army had mobilized approximately 500,000 men, but many of them deserted before the fighting ended. Others, following the national tradition, slipped away to carry on guerrilla warfare. Chetnik (eetnici ) units had been organized before the invasion began, and later Partisan groups also were formed.