His father Commander John Lamb was a Commercial Banking Company of Sydney director, as were his brothers Walter Lamb, Alfred Lamb and John de Villiers Lamb. His sister-in-law by John de Villiers Lamb, Henrietta Lamb, was the sister of the deputy chairman of the Commercial Banking Company of Sydney, Thomas Smith.[3] His sister-in-law via Walter was Margaret Dangar, daughter of Australian politician and explorer Henry Dangar.[4]
Early life
Lamb was born in London to the banker and politician John Lamb and Emma (née Robinson). His mother Emma Lamb (née Robinson) was the daughter of the deputy chairman of Lloyds Bank. His family migrated to Sydney in 1829, and, after his education, Lamb became a clerk in his father's mercantile firm and later became a partner.