May, 1940:
After a successful invasion and occupation of Poland, Germany sets it's eyes towards the west. More specifically, towards France. However, France had set up a series of forts and military bases along the Alsace-Lorraine, defenses which they could never hope to penetrate so they decided to invade through the Netherlands and Belgium. Dutch and Belgian forces were quickly demolished by German airborne forces and Blitzkrieg tactics, many of these forces surrendering after a couple of days. British, French, and Belgian troops reinforce their position in Belgium against the quickly advancing German Army but this attempt was largely unsuccessful. By the 14th of May, the main German force had moved into the river muse. France had no strategic reserves for a situation such as this, and by this point Britain begun planning Operation Dynamo. On the 21st of May, commander of the BEF General Viscount Gort launched an attack from the French town of Arras but had failed miserably. By the 22nd, German tanks under General Heinz Guderian had led the Allied forces into a trap, forcing them into the port city of Dunkirk. It was the only city left that wasn't under German occupation, and they would continue their assault until Dunkirk was captured and the nearly 338,000 soldiers were annihilated. The RAF suffered heavy loss as well. The failure of Operation Dynamo is hailed as a national tragedy, and an embarrassment. Churchill had promised to bring the boys safely home, yet none arrived on Britain's shores. Overall, Churchill's failure dips his popularity among the British populous and lessens the morale of Britain and France to come. Germany continues it's advance towards France.
July - September 1940:
On the 16th of June, the Battle of France had concluded with France surrendering to Germany. The entirety of Northern France is occupied by the Third Reich, and a puppet government is established in the south known as Vichy France. With France contained, Hitler sets his eyes on Britain. He had originally hoped that the British government would compromise for peace, hopefully on favorable terms, but Churchill made it clear that they would be doing no such thing. Even after Churchill's declaration, Hitler believed it to be a mere bluff. However, reality set in, and it was on July 2nd that Hitler considered the possibility of invading England much like they did France. On July 16th, he ordered preparations for such a thing and it was codenamed Operation Sea Lion. German High Command knew that they weren't ready for such a thing. Their army was in no way, shape, or form prepared for something such as this. The troops had been given no training for landing operations, and nothing had been done to build landing craft for the purpose. All that could be attempted was to collect shipping, bring barges from Germany and the Netherlands, and give the troops some practice in embarkation and disembarkation. Moreover, they feared about what would happen when the Royal Navy arrived on the scene. Their own navy was comprised of mainly modified riverboats that had to be pulled via tugboats as they couldn't drive themselves. It was made that the Luftwaffe be placed in charge for dealing with the Royal Navy, and also driving the RAF out of the sky to make the whole invasion easier. Beginning with bomber attacks against shipping on July 10 and continuing into early August, a rising stream of air attacks was delivered against British convoys and ports. Then, on August 13, the main offensive—called Adlerangriff (“Eagle Attack”) was unleashed, initially against air bases but also against aircraft factories and against radar stations in southeastern England.
The underlying object was to wear down Britain’s air defense, and indeed they did. Because of these bombing raids, RAF production was severely hurt and fighter command could only mass 600 frontline fighters to protect the British homeland. Winston Churchill launched a bombing raid over Berlin in response. Though small and ineffective, Hitler in our timeline was so enraged by this he ordered the Luftwaffe's attention be focused on London. This gave time for the British to prepare, and eventually gain air superiority over the Germans. However, in this timeline, the Luftwaffe continues to strike key RAF factories and radar stations which hinders the RAF and eventually allow the Luftwaffe to gain the air superiority over the RAF by September.
October, 1940:
A few weeks prior to the Luftwaffe's victory over the RAF, Italy began their invasion of the Suez Canal from their colony in Libya. Unlike our own timeline, Italy has a competent military and competent leadership. Why is this? I'm not going to specify. But for simplicity's sake, Mussolini puts the right guys in the right places and modernizes the Italian military so that it's more prepared for a 1940s-style war instead of pocketing the money that they had for himself. They were able to successfully invade and conquer Greece without help from Germany, meaning the Germans themselves don't invade Yugoslavia. Now, Italy is limited in terms of resources at least more limited when compared to it's allies and Mussolini knows this. He decides to invade the Suez Canal in hopes of capturing vital oil fields. With the British military presence limited in Egypt due to the Anglo-Egyptian treaty of 1936, most of it's forces are concentrated on the Suez Canal and Red Sea Route. In days, the city of Sidi Barrani is captured without the deadlines that plagued the Italian Army in our own timeline and soon the entirety of Egypt is conquered soon after. This effectively splits the British Empire in half, as now they would have to take the cape route instead of the shorter Suez route. This makes British reinforcements to it's colonies in the Middle East impossible. It's colonies of Palestine, Lebanon, Transjordan, and Iraq are all captured. This gives the Axis major oil fields. Using a force of around 90,000 Italians and 200,000 natives (a number which is historically accurate), Italy invades Sudan which is unreinforced with the loss of Egypt. Next, they use their remaining forces to invade British Somalia.
December, 1940:
The British are, frankly, in a catastrophic state. The RAF and the Royal Navy have been nearly destroyed and their major cities like London, Bristol, Birmingham, Liverpool, Manchester, Plymouth, Portsmouth, Sheffield, and Southampton have all been destroyed from constant bombing raids with the British unable to protect themselves. Winston Churchill has lost a lot of support