 He completed a military course conducted by Zygmunt Zieliński, a future Polish Army "generał broni" (lieutenant general).In 1923 Pełczyński married Wanda Filipowska, with whom he had a daughter, Maria, and a son, Krzysztof (Christopher, born 1924, who died during the Warsaw Uprising on 17 August 1944, of wounds sustained on 1 August, the first day of the Uprising).The outbreak of World War I in August 1914 found Pełczyński on vacation near Włocławek.