Fr Nadson was born Aliaksandar Bočka () in the village of Haradzieja near Niasviž, the Second Polish Republic (nowadays Minsk Region of Belarus) into a middle-class family. His father Anton had served as an officer in the army of the Russian Tsar in the First World War, and had participated in the 1920 anti-Bolsheviks Slutsk Uprising. Nadson studied at the Teacher Training College in Niasviž seminary. In 1944 he emigrated from Belarus, and in 1945 was a soldier in the 2nd Polish Corps fighting in Italy, where he was wounded.