 Nothing is known, at present, of Mroczkowski's family background or childhood.As the earliest written record, the diary of his uprising colleague, Szymon Kotylla published in 1907 indicates, that he was a student at the Medical Academy in Warsaw (1860-1861), he would have had access to funds for his interrupted studies and for travel to Italy for military training.As a convinced patriot he went to Cuneo in Italy to attend the Polish military cadet school (1861–62), commanded by Ludwik Mierosławski in preparation for a future uprising.On his return to Poland in 1862 the National Central Committee despatched him with the "Nom-de-guerre", "Wincenty Kamiński", to the Augustów Governorate, under cover of being a journalist, to help organize military units.