When the Germans took Belgrade with only seven soldiers

Italian dictator Benito Mussolini sent 500,000 soldiers to the Balkans, and in the first six months, he lost 63,000. The overriding height and snowy weather that lasted until May did not allow the German convoys to reach supplies, and victory depended more on the line of secure supply than military power, Historynet writes.

All the key sites had to be invaded quickly, and the main targets were cities. The Germans expected Greece's surrender, so Athens and Greek ports would fall into their hands. In this way the Greek base of German Air Force Luftwaffe and the Kriegsmarine Sea Force would strengthen control in the northeast Mediterranean and help supply troops to Africa.

Fears that Pavle Karadjordjevic could side with the fascist wing prompted Yugoslav Ambassador to Washington to send a petition to Belgrade, calling on the Serbian prince not to surrender to Nazi leader Adolf Hitler.

British King George VI and Prime Minister Winston Churchill sent a message to Karadjordjevic and Yugoslav Prime Minister Dragisa Cvetkovic. Churchill predicted that if Yugoslavia becomes a participant in the Greek murder, its destruction will be safe and irrevocable”.

On March 20th, Karadjordjevic officially announced that his country would join the Trepal Pact. At a meeting with US Ambassador Arthur Blies Lane, he stressed that if he does not join the Pact, he will not be able to account for the support of Croats in the German invasion.

On March 24th 1941, Prime Minister Tsvetkovic and Foreign Minister Aleksandar Cincar-Marcovic traveled to Vienna in secret. The agreement was signed on March 25th and returned home. In Belgrade they faced the coup that started on the night of March 26th. Yugoslav military officials seized military bases, planes and government buildings, bringing down the weak Yugoslav government overnight.

Cvetkovic was arrested. Prince Karadjordjevic was captured in Zagreb and was forced to leave the post. The new government announced it would remain loyal to the Trepal Pact. On April 6, 1941, German Foreign Minister Joachim von Ribbethrop ordered an attack on Yugoslavia.

Belgrade suffered several days of bombing and was occupied much earlier than planned on April 12th 1941, thanks to a handful of small arms led by the Captain of the Waffen Forces Unit, Fritz Klingenberg, a 26-year-old man who has earned the reputation of a stubborn man.

“Klingenberg is intelligent, but stubborn, loyal, excellent under pressure, but arrogant to the extent of his hearing”, commemorates one of his former commanding officers.

Reaching Belgrade was not easy, and after several hours of surveillance that made the city, one of Klingberg's men found an abandoned boat on the Danube River.

Klinberg had only six soldiers with him but decided to dig deep into the city center. They slowly advanced in prison clothes, crossing checkpoints without causing any doubt.

Klingenberg ordered group leader Hans Hosfelder to remove the Yugoslav flag into the city and replace it with the German on 12 April. On his orders, soldiers began patrolling the streets, ordering citizens that they have already taken the city, while the mayor of Belgrade obeyed Klingenberg's ultimatum for unconditional surrender.

In this way, he and a small group of people took the city, captured 1,300 soldiers delivered without firing a single bullet, and opened the way for other German forces to reach the city.

For his courageous act, Klingenberg was honoured with the Iron Cross and became a favourite in Nazi circles. When the Soviet Union's conquest began, Klingenberg once again demonstrated strategic skills in the battles in Krakov, Minsk, and Kurska as he was killed on March 23, 1945.