Friedrich August von Hayek was born in Vienna to August von Hayek and Felicitas Hayek (née von Juraschek). Friedrich's father, from whom he received his middle name, was also born in Vienna in 1871. He was a medical doctor employed by the municipal ministry of health, with passion in botany, in which he wrote a number of monographs. August von Hayek was also a part-time botany lecturer at the University of Vienna. Friedrich's mother was born in 1875 to a wealthy, conservative, land-owning family. As her mother died several years prior to Friedrich's birth, Felicitas gained a significant inheritance which provided as much as half of her and August's income during the early years of their marriage. Hayek was the oldest of three brothers, Heinrich (1900–69) and Erich (1904–86), who were one-and-a-half and five years younger than him.

Who was Hayek's father?