One of the reasons Wilhelm hesitated to attack Greece was the Battle of Crete, also known as the "graveyard of German paratroopers."
Crete, located at the exit of the Aegean Sea, was a vital maritime route from Western Europe to the Middle East. The northern part of the island consisted of hills, while the rest was mountainous, with Mount Ida reaching an altitude of 2,456 meters. There was a simple road along the northern hills, and other areas had only footpaths, making troop movements inconvenient. The island had a population of over 80,000, concentrated in places like Málama, Chania, Sougia, Rethymnon, Ierapetra, Nicopolis, and Sittia, with the capital located in Chania. Currently, the island had three airports: Ierapetra Airport, capable of handling various aircraft; Málama Airport, only suitable for fighter aircraft; and Rethymnon Airport, still under construction.
To carry out the airborne assault on Crete in the original timeline, the German military deployed 22,000 paratroopers, over 500 transport planes, 100 bombers, and 100 gliders. The German forces established an airborne campaign command under the leadership of the 4th Air Fleet. It included the 11th Airborne Corps commanded by General Student, primarily responsible for ground operations; the 8th Air Fleet commanded by General Richthofen, mainly providing air support; and the Southeast Naval Fleet commanded by Admiral Schuster, deploying 70 various naval vessels to support the airborne operation. General Löhr, the commander of the 4th Air Fleet, served as the overall commander for the airborne campaign, and Major General Süssmann commanded the ground forces of the 7th Airborne Division.
On May 14, 1941, the German forces gathered at the airborne departure area near Athens. On the 18th and 19th of May, the German Luftwaffe conducted frequent bombings of the island's targets.
On the other hand, Churchill intended to defend Crete. The island's defending forces consisted of 42,000 soldiers (approximately 28,000 British troops and 14,000 Greek troops), with six tanks and 35 aircraft. In late April, General Wavell, the Middle East Commander-in-Chief, appointed Major General Freyberg of New Zealand as the overall commander of the defending forces on the island. Brigadier Puttick was subsequently appointed as the brigade commander. Following this, the defending forces adjusted their troop deployment based on intelligence reports.
On May 16th, the British forces shot down a German reconnaissance plane over Crete and learned that the Germans were planning an airborne assault on the island within the next 48 hours. Consequently, the defending forces on the island went on high alert on May 17th.
During the 12-day conflict, the Allied forces suffered 15,743 casualties in the army (killed, wounded, or captured), 2,011 casualties in the navy, and the air force lost 46 aircraft.
The losses for the German side were particularly severe compared to other conflicts since 1939. In the Balkan Campaign just over a month ago, the German casualties amounted to only 5,650, while in Crete, the losses from the airborne units alone reached 7,000 (there is significant discrepancy in different sources, with some claiming that the 7th Air Division alone had 3,250 killed or missing, 3,400 wounded, and the parachute assault regiment alone had 700 killed or missing).
What pained the German high command even more than the loss of thousands of well-trained paratroopers was the substantial loss of aircraft, exceeding 350, with more than half of them being transport planes. Crete was henceforth known as the "graveyard of German paratroopers." Consequently, the German military refrained from using large-scale airborne assaults in future military actions. Paratroopers were primarily deployed as elite infantry in ground combat. Although they achieved classic defensive battles like the Italian defense in the Battle of Cassino, considering their specialized airborne training, this seemed somewhat underutilizing their capabilities. It's worth noting that without the tenacious fighting spirit of the elite paratroopers on Crete, other Western forces or even German regular army units might have surrendered or suffered more extensive casualties.
The airborne operation on Crete marked the world's first example of independent paratrooper combat. Through this operation, countries around the world recognized the absolute necessity of ground forces being able to maneuver through the air, leading to the formation of large-scale airborne assault units.
As for the other country in the Balkan Peninsula, Wilhelm decided to intervene, while he had no intention of letting these valuable paratroopers sacrifice themselves in vain. As long as Greece truly maintained its neutrality and did not conspire with Britain, Wilhelm had no plans to concern himself with Greece.
The Kingdom of Yugoslavia (1918–1945) was a monarchy located on the Balkan Peninsula, established by the Serbian Karađorđević dynasty to unite the Southern Slavic peoples. It began with the acquisition of Croatia, Bosnia, and Herzegovina from the Austro-Hungarian Empire after World War I and continued until the invasion by the Axis powers, leading to the establishment of the Socialist Federal Republic of Yugoslavia under Tito. Its territory included present-day Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, Slovenia, and Croatia, as well as Kosovo in Serbia.
Originally named the "Kingdom of Serbia," it later changed to the "Kingdom of Serbia-Croatia-Slovenia" and was finally renamed the "Kingdom of Yugoslavia" in 1929.
The current ruler, Prince Paul (leader of the regency council after the death of the old king), is pro-German, agreeing to cooperate with Germany and signing an agreement. In the original timeline, this Prince Paul also signed a similar agreement, leading to a military coup in Belgrade led by General Dušan Simović, the Chief of the Yugoslav Air Force, arresting current government officials and enthroning 18-year-old Peter II as king.
However, these individuals soon realized their lack of support, as Britain was preoccupied and incapable of assisting them, while Germany loomed nearby with overwhelming power. They had no means to resist Germany effectively. If they declared the agreement invalid, it would only further anger Germany. Therefore, they promptly issued a statement expressing loyalty to the agreement signed by Prince Paul.
Yet, this proved to be futile, as Hitler's fury could not be appeased. Simultaneously, this vacillation within Yugoslavia caused internal chaos. The populace and officials struggled to discern any difference between the current government of Peter II and the previous government of Prince Paul, leading to low morale. Those in government offices and the military, who were proteges of Prince Paul, harbored distrust toward the current government and were more inclined toward the Germans. Hence, from the beginning of the war, the morale of Yugoslavia had already plummeted, signaling their failure in terms of morale.
This time, the special forces secretly dispatched by Wilhelm launched a surprise attack on the secret meeting point of Dušan Simović and others, killing most of the high-ranking officers prepared to participate in the coup. Peter II was arrested and placed under house arrest, turning into a foreign version of Liu Bei. Consequently, Yugoslavia remained under the control of the pro-German faction.