[2] Grunfeld was born in Breslau (today Wroclaw) in the Prussian Province of Upper Silesia to an assimilated Jewish family with longstanding interests in the steel and chemicals industries.

Later, Grunfeld had to confront critical problems posed by the aftermath of hyperinflation, industrial unrest and world depression following the Wall Street crash of 1929.

He was able to use his status as an honorary Consul of Spain to avoid deportation to a concentration camp and fled to London with his family shortly after the Night of the Long Knives.

[7] Exiled in London, after a period of operating an independent factoring business, Grunfeld joined forces with Siegmund Warburg in the New Trading Company, which was established to help refugees from Europe extract their money from their native country and invest it safely.

After the outbreak of war, Grunfeld successfully avoided internment as an enemy alien by leaving his home every morning at 7am and walking around Hyde Park—it was thought that the police typically made their arrests between 8am and 9am.

S.G. Warburg rose to international prominence after it pioneered the hostile takeover in the UK with the acquisition of British Aluminium by Reynolds and Tube Investments in 1959.