He was born in Friedberg, Germany in 1862 into a Jewish banking family, travelled first to London in 1880, where he was naturalised British, and then to Kimberley, South Africa in 1884 to work in the diamond industry for Dunkelsbuhler and Company alongside his cousins Louis Oppenheimer and Fredrich Hirschhorn.
Gustav Imroth later represented Barnato Brothers in their dealings with the diamond syndicate (later De Beers), working closely with Solomon Joel and Ernest Oppenheimer (also a first cousin). He helped found the Johannesburg Consolidated Investment Company Limited (“Johnnies”) and was its managing director from 1911 to 1920, when he retired to London. Lieutenant Leslie Imroth of the 11th Hampshire Regiment died in 1918 of wounds sustained during the Great War.
