Oliver Brian Sanderson Poole was born at 6 Montagu Mansions, St Marylebone, London, on 11 August 1911, the only child of Donald Louis Poole, an insurance broker and a member of Lloyd's of London, and his wife Therese Lillian née Frodsham.

[9] He was also appointed to the American Legion of Merit as a Legionnaire "in recognition of distinguished services in the cause of the Allies" on 15 March 1945,[10] and to the Dutch Order of Orange-Nassau with Swords (denoting the military division) as a Commander on 16 January 1947.

In the 1958 Birthday Honours, he was raised to the peerage,[12] and was gazetted on 11 July as Baron Poole, of Aldgate in the City of London.

He joined the family business, John Poole & Son Ltd, insurance brokers, in the city, in 1939, and became a member of Lloyd's.

He oversaw the expansion of the company through the acquisition of the Financial Times, Penguin Books, Longman, Château Latour, and Royal Doulton.

From 1950 to 1965, he was a director of Lazard Brothers & Co, a London merchant bank in which Pearsons owned 80 per cent of the stock, and was its chairman from 1965 to 1973.