 He was born in London on 29 August 1733 and christened in Much Hadham in Hertfordshire on 14 December 1733, second son of Roger Metcalfe (1680 – 5 January 1744-5), a surgeon of Brownlow Street now Betterton Street, Drury Lane, London and Jemima Astley (born on 3 August 1703).Metcalfe was named after his grandfather Sir Philip Astley (1667–1739), 2nd Baronet of Hill Morton.Jemima Metcalfe married afterwards to Henry Groome, a limen-draper of St Paul's, Covent Garden and who was also the Keeper of the Guildhall and a member of the Worshipful Company of Musicians.