The European War was a war between the countries of Europe. It lasted from 2017-2026, costing 45,000,000 lives.
Three years before the war, another war took place: The Balkan War. It was between Serbia and its allies (Montenegro, Macedonia, Romania, Slovenia) and Greece and its allies (Croatia, Bosnia & Herzegovina, Albania, Kosovo). Serbia won the war, and forced Greece to give up all territory north of Athens, and then forced Albania to give up lands north of Durrazo.
One year later, violent Communist revolts took place in Romania and Bulgaria, caused by illegal Russian immigrants. The revolt in Romania succeeded, and it became the Socialist Republic of Romania. The Bulgarian revolt failed, and the Bulgarian government passed many strict immigration laws.
Meanwhile, the Serbs were building up their military forces. In 2015, the National Serbian Air, Land, and Sea Assault Squad (or the military) had 40,000,000 troops, 156 ships, 542 tanks, and 560 planes. The Balkan countries, especially Croatia and Greece, feared a Serbian invasion. In two years, their fears would be confirmed.
January 16th: Serbia invades remaining parts of Greece, Croatia declares war on Serbia.
January 19th: Montenegro and Macedonia ally with Serbia, forming the Imperial Balkan Alliance.
January 23rd: Greece invades Serbian-controlled Northern Greece.
January 26th: Greece takes Northern Greece and Macedonia, Croatia invades Serbia.
February 4th: Romania allies with Serbia, and invades Bulgaria.
February 16th: Austria joins Croatia.