In July 1768, Benyovszky travelled to Poland to join the patriotic forces of the Polish-Lithuanian Commonwealth, who had organised resistance in the Confederation of Bar (Konfederacja Barska), a movement in rebellion against Polish king Stanisław August Poniatowski, lately installed by Russia. In April 1769, he was captured by the Russian forces near Ternopil in the Ukraine, imprisoned in the town of Polonne, before being transferred to Kiev in July, and finally to Kazan in September.   An escape attempt from Kazan brought him to St Petersburg in November, where he was recaptured and sent to the far east of Siberia as a prisoner. In the company of several other exiles and prisoners – most notably the Swede August Winbladh, and the Russian army-officers Vasilii Panov, Asaf Baturin and Ippolit Stepanov, all of whom played a major role in Benyovszky's life in the next two years – he reached Bolsheretsk, at that time the administrative capital of Kamchatka, in September 1770.