 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 clerk, Cyril Batchelor.He was elected a bencher of the Inner Temple in 1950, and appointed Recorder of Cambridge, a part-time judge, in 1952; he had previously served as Recorder for Rye from 1944 to 1951.In 1954 he represented the government of British Kenya during Jomo Kenyatta's unsuccessful appeal against his conviction for membership of the rebel Mau Mau; Kenyatta was a moderate, and is now considered unlikely to have been a member of the organisation.