Following a long hiatus caused by the pandemic, the Research Centre for Armenian Culture in Poland held its first ‘normal’, that is, face-to-face, seminar on Friday 25 June at 16.00 on its premises. The discussions were led by Professor Krzysztof Stopka and Dr Marcin Łukasz Majewski, who are the editors of the latest volume in the Testaments of the History of the Polish Armenians series. They reported on the work they have done on the reading, translation into contemporary Polish, and critical appraisal and preparation, of a source important to the history of the Polish Armenians that is now kept in the Mekhitarist Monastery in Vienna. This is the Register of the Armenian Cathedral in Lviv for 1635-1732, which is written in Armeno-Kipchak, Old Polish, and Latin, and which records baptisms and, in some cases, marriages and deaths. The seminar touched upon various aspects of the research potential the register offers for the analysis of the customs, anthroponymy, genealogy, demography, and migration of Polish Armenians, as well as of the Polish language of the eastern borderlands, and ethnic relations and acculturation processes in Old Poland.