Sergiusz Piasecki was born on April 1, 1901 (or June 1, 1899) in Lyakhavichy, then in Northwestern Krai of the Russian Empire (now Brest Province, Belarus).
In the monograph about his life, work and legend,[REF] researcher Krzysztof Polechoński noted that most available data about Piasecki's whereabouts often do not correspond to reality, not to mention the claims made by the writer himself.