Ukraine (Ukrainian Ukraina), country in eastern Europe, and the second largest country in Europe after Russia. Ukraine is bordered on the west by Poland, Slovakia, and Hungary; on the southwest by Romania and Moldova; on the south by the Black Sea and Sea of Azov; on the east and northeast by Russia; and on the north by Belarus. The Crimean Autonomous Republic—encompassing the Crimean Peninsula, or Crimea, in the south—is included in Ukraine’s borders.
Much of Ukraine is a fertile plain suited for agriculture. Ukraine is rich in natural resources, and has a developed economy with significant agricultural and industrial sectors. The country has a democratic form of government headed by a president.
From the 9th century ad northern Ukraine was part of Kievan Rus, the first significant East Slavic state, which succumbed to the Mongol invasions of the 13th century. Ukraine was for centuries thereafter under the rule of a succession of foreign powers, including Poland and the Russian Empire. In 1918 a Bolshevik (Communist) government was established in Ukraine, and in 1922 the Ukrainian Soviet Socialist Republic (SSR) was one of the four founding republics of the Union of Soviet Socialist Republics (USSR). Ukraine’s declaration of independence, approved by a popular vote on December 1, 1991, was a major factor in the USSR’s collapse later that month.