Started my campaign as Poland. In the span of three years, Poland became a monarchy under Michael I Hohenzollern, formerly the King of Romania. I invaded Lithuania and annexed it into my territory, turning Poland into the Poland-Lithuanian Commonwealth. Afterwards, I made inroads with Romania, planting the seeds for Michael to usurp his father Carol II. With that succeeded, the new empire was renamed into the Kingdom of Poland-Romania. In 1938, with the German annexation of the Sudetenland and Anschluss, Poland-Romania felt it was time for it to try its hand at demanding land. Poland-Romania successfully pressured Czechoslovakia into giving up its entire Slovakian land, rendering it to merely the Czech Republic (soon to be swallowed by Germany).
Hungary was the next in line to be swallowed by the new Major Power of Europe. Hungarian dictator Miklos Horthy was stuck between a rock and a hard place. On one hand, Horthy was on friendly terms with Adolf Hitler by 1938, and was on the cusp of an alliance with Nazi Germany. On the other hand, Poland-Romania were his ideological and cultural kinsmen, with a deeply shared history dating hundreds of years. Horthy sided with his kinsmen and allowed Michael I to claim the vacant throne of Hungary.
By now, the Kingdom of Poland-Romania began to appear stronger than Hitler and Josef Stalin of Soviet Russia could believe. Not only had they stabilized their country into a monarchy, but they had managed to unite the majority of Slavic countries: Poland, Romania, Lithuania, Slovakia, and Hungary. It was Hitler's worst fear realized: A united Slavic state. On the other side, Stalin was also mightily upset at these developments; with a massive buffer-state between the Soviets and the rest of Europe, this meant that for Communism to spread was to seek more creative means, or use force of arms. This led to the Molotov-Ribbentrop Pact of 1939, where both nations agreed on a non-aggression pact in favor of dealing with this Polish threat.
In July 1939, Adolf Hitler demanded Danzig and several territories of this Polish empire. Michael I denied this request and prepared his armies for war. Nazi Germany declared war against Poland mere days later, but Poland-Romania had an ace in the hole: Allies. Specifically, France and England had not stood idly by while Germany's aggression grew. Sure, they appeased him when it came to Austria and the Sudetenland... but they too built up their armies and prepared for the great conflagration that seemed inevitable. So from the West, France invaded through the Maginot Line, and Poland-Romania invaded through Brandenburg and Bavaria. It was a smashing success and within weeks, Berlin was captured.
Then came the Soviet Union's turn to complicate things. They declared war shortly after the Fall of Berlin. The Eastern Front was not as well prepared for war as the Western Front of Poland was, but they held strong off the back of the mighty Romanian Army and the Army of the East's defense. In the West, Hamburg was captured, and then Ulm was finally captured, where Hitler then shot himself and unceremoniously died. Germany capitulated not even 7 months, before the new year of 1940. Poland took Berlin as a mighty prize, an excellent addition to their empire, and additionally created a buffer state known as the Principality of the Rhine. France, for their part, instead formed Germany proper, to be a new ally for future wars.
Now comes the mighty task for Poland-Romania: Beating back the howls of Communist Soviets everywhere.
