Oswald Arnold Gottfried Spengler was born on 29 May 1880 in Blankenburg, Duchy of Brunswick, German Empire, the oldest surviving child of Bernhard Spengler 1844–1901), an official in the post office, and Pauline Spengler (1840–1910), née Grantzow, the descendant of an artistic family. Oswald's elder brother was born prematurely (eight months) in 1879, when his mother tried to move a heavy laundry basket, and died at the age of three weeks. Oswald was born ten months after his brother's death. His younger sisters were Adele (1881–1917), Gertrud (1882–1957), and Hildegard (1885–1942). Oswald's paternal grandfather, Theodor Spengler (1806–76), was a metallurgical inspector ("Hütteninspektor") in Altenbrak.