1654, Ukrainian cossack leader Khmelnitski signed the Treaty of Peleyaslav with the Russian czar, inviting Russia to rule eastern Ukraine. Since then, the eastern part of Ukraine (the left bank of Dnieper River) has officially merged with the Russian Empire, and the history of alliance between Ukraine and Russia has begun.
/kloc-in the 9th century, most of Ukraine was annexed by the Russian Empire, and the rest was occupied by the Austro-Hungarian Empire. During the chaotic period of the First World War and the Russian Revolution, it was temporarily independent as the People's Republic of Ukraine. The Ukrainian Soviet Socialist Republic was founded in 19 17 and merged into the Soviet Union in 1922, becoming one of the Soviet republics. The declaration of sovereignty was adopted on 1990. 199 1 regained its independence on August 24th.