Supposed to have been a deacon called Sidorka, he appeared suddenly, from behind the river Narova, in the Ingrian town of Ivangorod, proclaiming himself the tsarevich Dmitry Ivanovich, on March 28 1611. The Cossacks, ravaging the environs of Moscow, acknowledged him as tsar on March 2 1612, and under threat of vengeance in case of non-compliance, the gentry of Pskov also "kissed the cross" (i.e., swore alegiance) to the thief of Pskov, as he was usually nicknamed. On May 18 1612 he fled from Pskov, was seized and delivered up to the authorities at Moscow, and was secretly executed there.