Large portion of Ukraine’s current territory formed part of the medieval state of Kievan Rus‘. After the breakup of Kievan Rus’, instigated by the Mongol invasion, the country was divided for several centuries between the kingdom of Poland, the grand duchy of Lithuania, and the Ottoman Empire, and by the 18th century it had been largely integrated into the Russian Empire and the Austro-Hungarian Empire. Briefly independent following the 1917 revolution, Ukraine became one of the original constituent republics (and the third largest) of the USSR. In 1991, on the dissolution of the Soviet Union, Ukraine became an independent republic
from Old Russian ukraina 'border region', from u 'at, beside' + kraĭ 'edge, border'