Eastern Europe is the eastern region of Europe. Originally, it referred to the countries that were under the influence of the Eastern Orthodox Church in Constantinople during the middle ages, which was in contrast to the West which referred to the countries under the influence of the Roman Catholic and later Protestant Churches. Later during the Cold War it meant the European countries that belonged to the Soviet Union, a definition that still persists today in these post-soviet states. Others describe Eastern Europe as a region of predominantly Slavic cultures, though other ethnic groups live there as well.