Claims to have been no other than Tsar Peter III, Grand Duke Peter Fedorovich. Founded the Skoptsi after he had a fit of convulsions and visions one night and was seized by the revelation that castration is the only path towards Salvation. This occurred shortly after his marriage to Catherine, who was not too pleased with this whole shananigan. He performed his own "sugery" with the Knife of Aqedah, which he received as a wedding present.

He claims to have been aware of his wife's plans to assassinate, and escaped, leaving his "double" to be killed in his place.
He changed his name, and went off to gather followers. While recruiting followers, he was arrested and sent to Siberia for several years, from which he escaped. He was granted an audience with the new Tsar in 1801. Tsar Alexander granted him his freedom and permitted the cult to grow. But the Tsar's advisors quickly convinced Alexander that Selivanov indeed posed a real threat, and so Alexander humanely ordered him confined to a monastery. Selivanov handed over leadership of the Skoptsi to Shilov, his most faithful disciple.
He died in 1825.