The present article contains rectifications and addenda to the biography of Michał Dzierżanowski, a famous adventurer and one of the leaders of the Bar Confederacy. In all likelihood, he was born around the year 1722 and not 1725 as has been assumed in the literature up until now. After he had enlisted in the French army, he was subsequently taken captive by the English in April 1744 while on his way to Flanders (earlier on, this event was reported to have occurred around the year 1744). It was confi rmed that in the years 1753–1754, he had served in the French army in India, where he was promoted to the rank of commander of the village of Chalambaram; it was also confi rmed that in 1761 he had visited Spain. Michał Dzierżanowski died on 25 March 1809 and not in 1808, as had been assumed earlier. The accounts of Claude-Carloman de Rulhiere and Henryk Rzewuski concerning Dzierżanowski’s foreign adventures prior to the year 1764 had also been partly verifi ed. Further research should bring about successive addenda to the biography of this adventurer.