プガチョフの乱
The Ural Cossacks (known originally as the Yaik Cossacks) resented the attempts by the central government to impose rules and regulations on them, and on occasions rose in rebellions. The largest rebellion, the Pugachev's Rebellion of 1773–75, involved not only the Ural, but much of south-eastern Russia, and resulted in a loss of the government control there. After its suppression, Empress Catherine issued a decree of 15 January 1775 to rename most of the places involved in the revolt, in order to erase the memory of it. Thus the Yaik River and the city of Yaitsk were renamed to the Ural River and Uralsk, respectively, and the Yaik Cossacks became the Ural Cossacks.