Yemelyan Pugachev
Yemelyan Ivanovich Pugachev () (c. 1742 – ) was a Russian Cossack who led a great popular insurrection during the reign of Catherine the Great, claiming to be her late husband, Emperor Peter III. Alexander Pushkin wrote a notable history of the rebellion, "The History of Pugachev", and he recounted some of the events in his novel "The Captain's Daughter" (1836).
Bulavin Rebellion
The Bulavin Rebellion (Astrakhan Revolt) is the name given to a war 
of Don Cossacks against Imperial Russia between the years 1707 and 1708. The war was led by Kondraty Bulavin, a democratically elected Ataman of Don Cossacks. The war was triggered by a number of underlying tensions between the Imperial government under Peter I of Russia, the Cossacks, and Russian peasants fleeing from serfdom in Russia to gain freedom in the autonomous Don area. It started with the assassination of Prince Yury Dolgorukov, the leader of Imperial army's punitive expedition to the Don area, by Don Cossacks under Bulavin's command. The end of the rebellion is associated with Bulavin's death in 1708.