After establishing a legal career in the field of insolvency, Stevenson served during the Second World War as a Deputy Judge Advocate General of the Armed Forces.

[7] Most of Stevenson's early legal work was in the field of insolvencies, "almost always with small fees", and he made steady progress until the outbreak of the Second World War in 1939.

[9] In 1945 he served as Judge Advocate at the war crimes trial in Hamburg of former personnel of the German submarine U-852, the so-called Peleus affair.

[10][11] The U-boat captain, Heinz-Wilhelm Eck, was accused of ordering his crew to open fire on the survivors of a Greek ship, the SS Peleus, which they had just torpedoed and sunk.

[13] In the late 1940s and early 1950s Stevenson started to build his chambers' high reputation for commercial litigation, together with Alan Orr and Leslie Scarman, supported by a notable barristers' clerk, Cyril Batchelor.

[19] According to fellow judge Eustace Roskill, Stevenson's "fluent delivery, distinctive voice, remarkable sense of timing, and pungency of phrase soon marked him out as an advocate of note.

[20] In 1955, aided by junior counsel Sebag Shaw and Peter Rawlinson, Stevenson defended Ruth Ellis against the charge of murdering her lover.

Stevenson's decision to keep his cross-examination of the prosecution witnesses to a minimum,[21] and his "near silent performance in court",[22] have been severely criticised by Muriel Jakubait, Ellis's sister.

[16][a] Stevenson was a leading member of the legal team assisting Sir Reginald Manningham-Buller during the failed prosecution of Dr John Bodkin Adams in 1957.

The prosecution's conduct of the trial has been heavily criticised,[25] and its decision to drop a second murder charge via a nolle prosequi was scathingly described by the trial judge, Patrick Devlin, as "an abuse of process", saying: "The use of nolle prosequi to conceal the deficiencies of the prosection was an abuse of process, which left an innocent man under the suspicion that there might have been something in the talk of mass murder after all".

[27] Journalist Rodney Hallworth reports that Stevenson said of Adams' decision not to give evidence in court "I firmly believe justice is not served by the present law.

"[36] In similar vein he told a husband involved in a divorce case that his decision to live in Manchester was "a wholly incomprehensible choice for any free man to make".

[39] Although Stevenson's direction was not in accordance with the law in 1964, Parliament introduced a form of caution under the Police and Criminal Evidence Act 1984 that reflects what he proposed.

Stevenson believed that it was the judge's duty to help prevent crime by imposing robust punishments on those found guilty,[2] and he became noted for the severity of his sentencing, which led to occasional calls from the "liberal establishment" for his resignation.

"[33] He remarked later that the Krays had only told the truth twice during the trial: when Reggie referred to a barrister as "a fat slob" and when Ronnie accused the judge of being biased.

[36] In 1970 he controversially gave what were seen as excessively long sentences to eight Cambridge University students who took part in the Garden House riot, a demonstration against the Greek military government that turned violent.

[36][d] In 1976 the Court of Appeal overturned three of Stevenson's decisions in a single day, and Labour member of parliament Marcus Lipton tabled another parliamentary motion calling for his removal from the bench.

[45] But Eustace Roskill cautions that "It would be wrong to judge Stevenson simply by the notoriety of a few cases .... he showed great mercy to those whom he saw to be victims rather than aggressors.

[2] He "turned her [his wife] out" after he discovered that she had been having an affair with Colonel Maurice Buckmaster, head of the French section of the Special Operations Executive (SOE).

He opened his campaign by declaring that in the interests of a clean fight, he would make no allusions to the "alleged homosexuality" of his opponent, Tom Driberg,[36] who heavily defeated him in the vote; Stevenson returned to his legal practice the following year.

[51] Following his retirement, Stevenson called for the restoration of the death penalty for all murders,[41] and made frequent guest appearances on television until his health and eyesight began to fail.