On the accession of Catherine II, in the summer of 1762, still more stringent orders were sent to the officer in charge of "the nameless one"; if any attempt were made from outside to release him, the prisoner was to be put to death. Under no circumstances was he to be delivered alive into anyone's hands, without an express written order in the Empress' handwriting. By this time twenty years of solitary confinement had disturbed Ivan's mental equilibrium, though he does not seem to have been actually insane. Nevertheless, despite the mystery surrounding him, he was well aware of his imperial origin and always called himself "Gosudar" (Sovereign). Instructions had been given not to educate him, but he had been taught his letters and could read his Bible. Since his presence at Shlisselburg could not remain concealed forever, its eventual discovery was the cause of his demise.