Treaty of Hadiach
The Pereyaslav Articles (, ) were concluded on October 27, 1659 between Yuri Khmelnytsky, the son of Bohdan Khmelnytsky, and the Russian tsar. The treaty drastically limited the Ukrainian (Cossack) autonomy. This second treaty was an aftermath of the Treaty of Hadiach from 16 September 1658 between the Cossacks and the Polish–Lithuanian Commonwealth, which granted many privileges to Cossacks and thus threatened Russian influence over Cossacks. The articles imposed severe restrictions on Cossack Hetmanate autonomy.