Dunin was born on 5 June 1907, the youngest child of Lucia (Łucja)
Taczanowska (1862–1917) and her second husband Count
Rodryg Dunin (1870–1928). He grew up at the
Granówko estate near
Poznań, the youngest of ten children. He had six older siblings by his mother's first marriage to Stanisław Niezychowski, and two full sisters and one full brother, children of his own father Rodryg. The
Dunin family crest is the
Łabędź (swan). On 28 December 1933 Dunin married Zofia Helena Werner (1910–1939), daughter of Poland's vice-Finance Minister
Edward Werner, and great-niece of Saint
Raphael Kalinowski. They had three children: Krystyna,
Stanley (Stanisław, named after Dunin's older brother), and Magda (Magdelena). Mobilized prior to the outbreak of
World War II, Dunin was drafted into the
Wielkopolska Cavalry Brigade under Gen.
Roman Abraham. Serving in the rank of
Porucznik (First Lieutenant) he commanded the
march squadron of the 15th Poznań Uhlan's Regiment. He joined the regiment with his unit on 8 September 1939, and took part in the
Battle of Bzura. His wife was killed the next day, at the age of 29. == In popular culture ==