Less than an hour after the bombing of Belgrade had commenced, the ground invasion got underway. “It is vital for the blow to fall on Yugoslavia without mercy. There must never again be a Yugoslavia,” Hitler had decreed. Yugoslavia’s neighbors had been bullied under the Tri-Partite Pact to join in or permit passage of German troops. Hungary’s foreign minister, who not long before signed a friendship treaty with Belgrade, alone made an honorable, if futile, protest—he shot himself.
The invasion had been so hastily ordered that some Wehrmacht units were still en route from as far as Germany, or just getting orders. Fully eight divisions would not get there in time, but those that were there proved enough to overwhelm the hapless Yugoslavs.
The German Twelfth Army and 1st Panzer Group attacked from Bulgaria, the German Second Army and Hungarian 3rd Army from Austria, Hungary, and Romania, and finally the Italian 2nd Army from occupied Albania. To meet the multisided onslaught, the Yugoslav Army had almost a million men. It was an army, though, with antiquated weapons, a transport system based on the sluggish oxcart (a Yugoslavian unit required a whole day to cover the distance an equally sized but motorized German one could speed across in an hour), and a defense plan stubbornly based on holding the entire 1,900-mile border instead of withdrawing to more defensible positions as the British had urged.
And just how weak these border defenses turned out to be was glaringly exposed as a German bicycle company jumped the gun and pedaled more than 10 miles before having to fire a shot! However, the greatest weakness of all for the Yugoslavian Army was its other, equally deadly, enemy—the one from within.
“It is a sad fact,” Ruth Mitchell was to bitterly comment, “that Yugoslavia, of all the small nations of Europe, is the only one in which a large portion of her army with its regular officers turned traitor to their oaths.” That portion she was referring to was the Croats, who saw the invasion as an opportunity to throw off Serbian rule and eagerly took with a long-simmering vengeance.
One Croatian officer had defected to the Germans three days before the invasion with Yugoslavia’s air defense plans, enabling the Germans to pinpoint targets, particularly government buildings, in bombing Belgrade, then to locate local airfields to catch and destroy the obsolete Yugoslav air force on the ground. More than 1,600 others, 95 percent of the Croatian officers in the army, also deserted to the Germans while Serbian officers by the hundreds were murdered by their Croatian troops.
Equipment was disabled, communications disrupted, transport diverted. Croatian soldiers would wave on or outright cheer passing German formations. One was notoriously filmed handing over his rifle and, with a stupid grin on his face, offering to shake hands as the German smashed the weapon on the ground and, with obvious disdain, walked away.
From her train window Ruth Mitchell watched Croatians celebrating, with the royal Yugoslav flag hung with contempt upside down. The train repeatedly came under fire from mutineers. “Suddenly a sharp burst of firing. The train jerked to a stop. Our soldiers, yelling raucous curses at the Croats, tramped down the corridor, jumped out and down the embankment. Violent firing continued for 10 or 15 minutes. I could watch the flashes of the guns as our Serbs hunted the traitors among the trees and shrubs along the embankment.”
She got a further glimpse of the hopelessness of Yugoslavia’s position when she met on the train a Montenegrin peasant, gaunt, clothes in tatters, rags around his feet instead of shoes, who told her how he had rushed off from home to fight armed with just a knife. “There were only big iron monsters—tanks in long rows coming down on us. And what use—what use are knives against tanks?” he kept repeating.
The terrain at times was a more stubborn adversary. German armor so rutted the dirt roads that oxen were seized from the Yugoslavs to pull supply vehicles. Skopje fell to the German Twelfth Army on the second day, sealing off the border with Greece. When the news hit Sarajevo, which he had reached, St. John knew what that meant. “Poor Yugoslavia was hemmed in on three sides. The necklace of steel was tightening…. And it meant that all those thousands of people in Sarajevo had only one way out now. The Adriatic!”
Good Friday in Sarajevo was anything but as the city was repeatedly bombed—St. John sadly watching soldiers shoot at the aircraft, then dance around thinking they had driven them off—and diamonds were being offered for gasoline. “It was a battle of wits, with no tricks barred,” St. John would say about the relentless hunting for gas. “Whenever we parked the Chevrolet anywhere, one of us had to stand guard to make sure some unscrupulous or hysterical refugee wouldn’t break the lock on the gas tank and siphon out our last drop of fuel.”
With panic full on, the scenes in Sarajevo’s cafes reminded him “of the New York Stock Exchange on a two-million trading day.” Luckily, St. John remembered an army depot outside of town; the officer in charge, resigned to the Germans coming, let him have all the gasoline he needed.
With the Yugoslav command structure destroyed by design in the bombing of Belgrade and the king and government on the run, Yugoslav forces in the field were leaderless. On his flight for the coast St.John met general staff officers who took their time dining and chatting with him. “Members of the Yugoslav General Staff, on the eve of a great military debacle, were spreading butter on salted biscuits and talking about things that didn’t matter and never had mattered and never would matter,” he would recall with dismay.
The Germans often simply bypassed what pockets of resistance there were. One Yugoslav unit made a desperate nighttime charge out of the woods against a village Germans were billeted in. Grabbing their boots, helmets, and weapons, the Germans, still in their underwear, soon drove off the attackers.
Racing 100 miles a day, the German Second Army rolled into the Croatian capital, Zagreb, on April 11, to be cheered for the first time in the war by a non-German population. The Ustachi declared independence and set up the most crazed, murderous, quisling regime of the war. “In the north of Yugoslavia the front is breaking up with increasing rapidity,” General Franz Halder of the German General Staff, who knew what they were doing, recorded in his diary. “Units are laying down their arms or taking the road to captivity. One cycle company captures a whole [unit] with its staff. An enemy divisional commander radios his superior officer that his men are throwing down their arms and going home.”
The German Twelfth Army had broken through a strong defense line of bunkers and antitank batteries then driven northwest 213 miles through the Morava Valley in seven days toward Belgrade. Other Wehrmacht units were closing in from the southeast, through Serbia where resistance had been the stiffest, and from the west, but all were beaten to the prize by a tiny unit of the hated rival, the Waffen SS.
A motorcycle assault company of the SS Das Reich Divison led by Captain Fritz Klingenberg and attached to the German Second Army reached the opposite, north bank of the Danube on the morning of April 12, 1941. Though the river was flooded, Klingenberg located a motorboat and with a lieutenant, a pair of sergeants, and five privates grandly set off to conquer a capital.
They were nearly swamped, but crossed successfully. On shore they surprised a score of Yugoslav soldiers who, at the sight of them, just dropped their weapons and threw up their hands. When Yugoslav military vehicles arrived shortly afterward, Klingenberg fired on them, boarded, and then headed into the ruined city.
With no one to stop him, he made his way to the wreck that had been the Ministry of War, then drove on, weaving through the rubble, to the German Legation. It was untouched. The Luftwaffe had spared the blocks around it.
The military attaché, Robert St. John noticed, had not left, and Klingenberg ran up the Swastika at 5 pm to proclaim Belgrade’s fall. The mayor appeared two hours later with what little authority he had left to make it official, and the next morning German armor crunched the debris to make it final.
The last major city left, Sarajevo, fell two days later. Cruelly fitting, the Yugoslav government official who surrendered the country had signed Yugoslavia’s first capitulation to Hitler in Vienna just a month before—Foreign Minister Aleksander Cincar-Markovich.
King Peter and Prime Minister Simovic had flown out from one of the few remaining operational airstrips incongruously aboard another German aircraft purchased during better days with Berlin, a Junkers Ju-88. Along the way they ran short on fuel and had to put down at a makeshift British airfield in Greece, with airmen rushing it with pistols in hand.