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).
Peter III of Russia
After his death, four fake Peters (five if Šćepan Mali of Montenegro is included) came forth, supported by revolts among the people, who believed in a rumor that Peter had not died but had been secretly imprisoned by Catherine. The most famous was the Cossack Yemelyan Pugachev, who led what came to be known as Pugachev's Rebellion in 1774, which was ultimately crushed by Catherine's forces. In addition, Kondratii Selivanov, who led a castrating sect known as the Skoptsy, claimed to be both Jesus and Peter III.