The Golden Age of Kievan Rus' began with the reign of Vladimir the Great (980–1015), who turned Rus' toward Byzantine Christianity.
The dominant religion in the country is Eastern Orthodoxy, which has strongly influenced Ukrainian architecture, literature and music.
It is a member of the United Nations since its founding, the Council of Europe, OSCE, GUAM, and one of the founding states of the Commonwealth of Independent States (CIS).
The first of these periods occurred briefly during and immediately after the German occupation near the end of World War I and the second occurred, also briefly, and also during German occupation, during World War II.
However, both of these first two earlier periods would eventually see Ukraine's territories consolidated back into a Soviet republic within the USSR.
Excluding Crimea, Ukraine has a population of about 42.5 million, making it the 32nd most populous country in the world.