Peter Morton's mother, the former Louise S Leatham, is the eldest of the four children of Dr Aubrey Gerald Leatham (23 VIII 1920-7 VIII 2012), of that landed gentry family, and his wife (marriage registered Q3 1954 - Leicester C), Judith Augustine Savile Freer (per company records, born in January 1932). Dr Leatham was a leading cardiologist, and headed the team at St George's Hospital in London which, in 1955, devised the first heart pacemaker.
Dr Leatham's maternal grandmother was Janet Edith Orr-Ewing (1854-1935), daughter of Sir Archibald Orr-Ewing, 1st Bt (4 I 1818-28 XI 1893). She was married firstly to Lt-Col Arthur Grey Hazlerigg, by whom she was the mother of Arthur Grey Hazlerigg, 1st Baron Hazlerigg (17 XI 1878-25 V 1949). Widowed, she was married secondly to Major Henry Pelham Burn, of that landed gentry family, by whom she was the mother of Kathleen Ella Pelham Burn (26 II 1892-1971), who married Dr Hugh William Leatham (14 VI 1891-22 XII 1973) on 18 April 1917; they were the parents of Dr Aubrey Leatham.