Background
Wilhelm Jensen was born at Heiligenhafen in the Duchy of Holstein (now Germany), the natural son of Swenn Hans Jensen (1795–1855), the Mayor of the city of Kiel, later administrator (Landvogt) of the German/Danish island of Sylt, who came of old patrician Frisian stock.
Education
After attending the classical schools at Kiel and Lübeck, Jensen studied medicine at the universities of Kiel, Würzburg, Jena and Breslau.
Career
Wilhelm Hermann Jensen abandoned the medical profession for that of letters, and after engaging for some years in individual private study proceeded to Munich, where he associated with men of letters. In 1872 he again returned to Kiel, lived from 1876 to 1888 in Freiburg im Breisgau, and from 1888 until his death was a resident of Munich and Saint Salvator near Prien on Lake Chiemsee.