In the east the expansion of Persia's Achaemenid Empire led to confrontations with the Greek cities of Asia Minor. With the support of Athens and Eretria these cities rebelled against the Persian king Darius I in 499 BC, and the rebellions were not finally suppressed until 493 BC. Darius then demanded the submission of all the mainland Greek cities, but Athens and Sparta refused. In 492 BC Darius sent out a punitive mission, which backfire...

The wars that began in 1991, when Yugoslavia broke up and five new sovereign states emerged, were Europe’s most violent conflicts since 1945. In 2006, although foreign intervention and mediation had stopped the fighting, the presence of international peacekeeping forces was still found necessary to prevent further large-scale bloodshed.After the 1939–45 war, in which Yugoslavia and Albania came under German and Italian control, communists...