Jenkins was educated at Charterhouse School and fought then with the 12th Battalion, Rifle Brigade (Prince Consort's Own) in the First World War.

[3] After the war, he went to Balliol College, Oxford, and graduated with a Bachelor of Arts in 1920, winning the Hertford and Ireland scholarship.

[3] He was made a King's Counsel in 1938 and subsequently served in the Royal Army Service Corps during the Second World War.

[5] Jenkins joined the High Court of Justice, Chancery Division in 1947 and on this occasion was created a Knight Bachelor.

[4] After another decade he was chosen a Lord of Appeal in Ordinary and in consequence was created a life peer under the Appellate Jurisdiction Act 1876 as Baron Jenkins, of Ashley Gardens, in the City of Westminster.