Grantham was born on 23 October 1835 in Lewes, Sussex, England to George Grantham and Sarah Grantham (née Verrall).[1] He was educated at King's College School, and was called to the bar in 1863 at Inner Temple.[1] He was appointed Queen's Counsel in 1877.[2]
Grantham married Emma L Wilson on 15 February 1865 in Sussex, England.[1] The couple had seven children. His eldest son's wife was granddaughter of British astronomer and chemist Warren de la Rue.[citation needed]
As a judge he was seen as competent but with a weakness for commenting on cases in a way that brought him into conflict with various groups, a habit that eventually led to hints in the newspapers that he should retire.[1] His tenure as a judge was mainly uncontroversial until 1906, when, co-determining petitions following the general election: for Bodmin, Maidstone and Great Yarmouth, he was seen as favouring the Conservatives.[1] A censure motion was proposed in the House of Commons and led to a vigorous debate, but the government declined to take it further, possibly because of the precedent it would set.[1]
Five years later, an indiscreet speech to the grand jury in Liverpool led to him being rebuked by the Prime Minister, H. H. Asquith, in the Commons,[5] 'one of the severest ever dealt to an English judge by a minister of the crown'.[1] He died later that year, of pneumonia, in his house, 100 Eaton Square,[6] London, aged 76,[1] also possessed of Barcombe Place, near Lewes, East Sussex.[6]
His probate was resworn the next year at £233,406 (equivalent to about £29,200,000 in 2023).[6]
