The 2008 Russo-Georgian War was a war between Georgia, on one side, and Russia and the Russian-backed self-proclaimed republics of South Ossetia and Abkhazia, on the other. The war took place in August following a period of worsening relations between Russia and Georgia, both formerly constituent republics of the Soviet Union. The fighting took place in the strategically important South Caucasus region. It is regarded as the first European war of the 21st century.