Defending the rights of believers in the East was an essential imperative of the ministry of Primate of Poland Cardinal Stefan Wyszyński. His activity in this direction was possible thanks to the extraordinary powers he received from successive popes. We do not know the details of Cardinal Wyszyński’s execution of his mission in the East. However, important in this context is a note drawn up by priest Michał Aronowicz from Grodno in Belarus, describing the circumstances of the handing over the unique primate’s powers to him in 1958. The document is held in the Polish Pontifical Church Institute in Rome archives.