To 1654 Ukrainians were creating one country with Polish-Lithuanian Commonwealth, but at the same time they were feeling as a second class citizens. For this reason in XVII century with the help of neighbouring Tsardom of Russia they’ve started the uprising and detached themselves from Polish-Lithuanian Commonwealth without creating new country. Instead according to the council of Pereyaslav from 1654 they choosed to be under rule of the Tsardom of Russia. After the mentioned council Republic of Polish-Lithuanian Commonwealth become weakend to the benefit of Tsardom of Russia. From this moment on Polish–Lithuanian Commonwealth have been in decline to the point when in XVIII century they lost their independance. After the First World War when Poland regained freedom under Józef Piłsudski an attempt was made to create an Alliance of independent countries lead by Poland as reaction to the Russian imperialism. The alliance called “Intermarium” included: Poland, Lithuania, Latvia, Estonia, Belaruse as well as Finland and Romania. To make the idea succesful Ukraine needed to be created but the idea failed to succeed. Instead independent Ukraine was created after the dissolution of Soviet Union even so Ukraine was still under immense influence of Russia. In 2014 Russia annexed during the war with Ukraine part of it – Autonomous Republic of Crimea. Till then Russia is trying to detach eastern provinces Ukraine. It is obvious that diplomatic relations between Russia and Ukraine became frozen. For this reason Poland and Ukraine may have opportunity to ally with other countries from region to stand against russian imperialism.