Fr Nadson was born Alyaksandar Bochka (Belarusian: Аляксандар Бочка, romanized: Aliaksandar Bočka) in the village of Haradzyeya near Nyasvizh, in the Second Polish Republic (now in Minsk Region, Belarus) into a middle-class family.

His father Anton had served as an officer in the army of the Russian tsar in World War I, and had participated in the 1920 anti-Bolsheviks Slutsk Uprising.

Nadson "had been guided on to this [ecclesiastical] path by (later Bishop) Ceslaus Sipovich, who himself had been sent by the Vatican to establish a Belarusian Catholic Mission in the UK".

Nadson "developed the institution to the point where it could justifiably be regarded as the foremost collection in the world, outside Belarus itself, of books (including many rare publications), maps, journals and artefacts relevant for the study of the complex area east of Poland once known as the Grand Duchy of Lithuania" with "a world-wide reputation" which "attract[ed] scholars from a wide range of countries".

The high regard in which his scholarship was held was shown by the award in 2008 of an honorary doctorate of the European Humanities University based in Vilnius.