 Gerd Sommerhoff and his twin sister were born in Wiesbaden, Germany, to Elizabeth Ruher and Walter Georg Sommerhoff, a wealthy banker who was born in New York to Elise Schumann, the second child of Robert and Clara Schumann.The Sommerhoff family resided in Haarlem, Netherlands, until the loss of the family fortune in the Wall Street crash and the death of their father "in compromising circumstances".The two younger children moved to Ryde on the Isle of Wight in 1931 with their mother Elizabeth Sommerhoff when she married Major Bernard Francis Anne Vernon-Harcourt, while their elder brother, Walter Hans Sommerhoff, emigrated to Santiago, Chile.