Background
He was the second eldest son of Frédéric Emile d'Erlanger, a banker working in Paris at the French branch of Emile Erlanger and Company and Marguérite Mathilde Slidell (1842–1927). His older brother, Baron Raphael Slidell d'Erlanger, who might have been more likely to follow his father into banking, was instead a scientist and professor at Heidelberg.
Career
Emile followed the banking route and from his father he was entrusted with presidency of the railway and tramway companies including the New General Traction Company in England. In 1891 he became a naturalised British subject. From 1911 he was chairman of the Channel Tunnel Company (the predecessor of EuroTunnel) and financed its design.
The company also financed the building of railways in Rhodesia, Angola and the Congo. She was the daughter of a landowner and shipowner in Le Havre. They lived in Falconwood, Woolwich, near Shooters Hill, south-east London, and also at 139 Piccadilly, the former home of Lord Byron.
Later they moved to America and lived in Beverly Hills. The couple had four children,
Robert (called Robin) Emile Frédéric Regis d'Erlanger (1896–1934)
Mary Liliane Matilda, called Baba, Baroness d'Erlanger (1901–1945),
Bianca, Baroness d'Erlanger.