ukraine was the first identifiable groups to populate what is now ukraine were cimmerians,scythians,sarmathians,and goths,among other nomadic peoples who arrived throughout the first millennium B.C. these peoples were well known to colonists and traders in the ancient world,including greeks and romans,who established trading outposts that eventually became city-states.slavic tribes occupied central and estern ukraine in the sixth century A.D.and played an important role in the establishment of kyiv.kievan rus prince volodymyr converted the kievan nobility and most of the populiton to christianity in 988 situated on lucrative trade routes,kyiv quickly prospered as the center of the powerful state of kievan rus.in the 11th century,kievan rus was the largest state in europe.conflict among the feudal lords led to decline in the 12th century.mongol raiders razed kyiv in the 13th century.