12th of December, 1939
After a period of planning and communicating, several armies from the Polish front were finally deployed to the West.
The Western allies proved to be unwilling to attack Germany, even through the Netherlands or France, giving the Germans ample time to prepare their forces for the upcoming invasion.
16th of March, 1940
Several new groups of interceptor planes had been readied over the last few months - previous to this, German interception was considered woefully underpowered. It was not expected that the airforces of Britain and France combined would crumble to the German airforce, but at least they presented a threat.
Germany declared war on Denmark today, with a 100k strong army. It was considered unnecessarily large, but the Germans feared the British might try to send some help to the Danes.
2nd of April, 1940
Denmark surrenders, only several minor skirmishes were ever fought against the much more powerful Germans. Just as they had done with Poland, France and Britain had sent little actual aid to Denmark, making this operation very easy. Many of the 100k-strong army were promptly sent back to the Netherlands.
14th of April, 1940
The 1.032-million strong army in the West was ready to invade France and the low countries. Belgium and Luxembourg were declared war on, and the entire border from the bottom of Luxembourg to the top of the Netherlands was about to become a battlefield.
18th of April, 1940
Luxembourgish resistance was shortlived, having no standing army. The Dutch were protected by their rivers, although German forces were nonetheless already slowly pushing them back. Belgium, with its shorter border with Germany, was completely protected by rivers and city fortifications, concentrated around the city of Verviers. A large part of the Belgian army in that region had been sent there in the three days of war, forcing Germany to commit a large part of its army in Belgium to attack the city.
19th of April, 1940
Having advanced through Luxembourg, the German forces there immediately started to attack the area behind the city of Verviers. Realising they were about to become surrounded, the Belgian defenders begun a hasty retreat to their river fortifications. Other forces in Luxembourg attacked the surrounding Belgian regions, whilst poorly executed French counter attacks were repelled with minimal effort.
The city of Liege, bolstered in the last few years against the ever growing German aggression, was now at the front line, heavily protected by not only artificial defenses - bunkers and tank traps, but also the important natural defense of a large river. Germany of course had the numerical superiority, France apparently refusing to help the Belgians, and it was not expected that this city could last forever. The north of the Netherlands was now completely under German control, and a few batallions were now attempting to clear the Afsluitdijk for a shortcut to Amsterdam and the south-west of the country.
24th of April, 1940
Germany had succeeding in pushing through the first set of rivers in the Netherlands.
The attack in the north was going well. A few French divisions finally fighting at the front presented little worry for the German forces, who were advancing to Amsterdam at an alarming pace.
5th of May, 1940
Having secured the Afsluitdijk, German forces were pouring in from the North. A key breakthrough south of Amsterdam threatened to cut off many Dutch forces from France, and Belgium had finally lost the city of Liege after intense casualties (numbering over three thousand from both sides).
Most Dutch forces were retreating to the south, to France, through the small border with Belgium; the Dutch had realised their position was untenable.
15th of May, 1940
Amsterdam had fallen, and the last few Dutch forces in the Netherlands were now concentrated to the south, in its many islands and waterways. Brussels was now under direct attack, but most of the Belgian divisions were caught up in Antwerpen, where yet another German attack was hours from being launched.
Note: I have not used any tactical bombers, though I am still using interceptors of course, as per the uh, request, of enewald.