The son of a law lord, Parker was educated at Rugby School and Trinity College, Cambridge.

This intention he abandoned on graduating in 1922 to read for the Bar (Lincoln's Inn) where he was called in 1924, entering the chambers of Donald Somervell.

The more measured style of the appellate courts suited Parker more than the cut and thrust of the King's Bench, and his ability to get to the important details of a case was assessed as good by those who appeared before him.

Macmillan therefore decided to appoint a senior judge, and Parker's name emerged as the one candidate with whom most people were happy.

[3][2] Parker's style was totally different from Goddard as he confined himself to the higher courts and did not intervene in everyday criminal trials.

He was called upon where a trial had a serious political aspect, and was criticised when he imprisoned journalists who refused to reveal their sources during the Vassall tribunal of 1963.

Parker was a mild reformer who supported legal aid and tried to modernise some judicial procedures which he thought were antiquated, such as the assize court system.

The most important speech he made was in debates during the passage of the War Damage Act 1965 which has the effect of retrospectively overturning the judicial decision of the House of Lords in Burmah Oil Co. v Lord Advocate thereby depriving the plaintiff of an award of damages.