William Wallace Stewart Johnston was born in South Yarra, Victoria, the son of Judge WE Johnston. He was educated at Melbourne Church of England Grammar School, leaving school in 1905. He entered Trinity College at the University of Melbourne and embarked on a medical course. However, after a year or two, he decided that medicine was not for him and he spent some time on a property in the Western District of Victoria. After a period he became disillusioned with the land. In 1910 he travelled to Europe with his father, the judge. The latter was suffering from angina and the journey was to ‘take the waters’. Following the Grand Tour he returned to Melbourne and resumed his medical course. He graduated MB BS in 1914 and obtained an appointment as resident medical officer at the Melbourne Hospital.

While he was an RMO at the Hospital, the First World War broke out and he enlisted in the AAMC. He served for two years as regimental medical officer to 12 Battalion. He won the Military Cross in 1917 and was awarded the Distinguished Service Order in 1918. He was also mentioned in dispatches. The official history records that he was one of the best RMOs in the AIF, an outstanding example of the part that a conscientious RMO could play in building and maintaining morale in a fighting unit. The awards are a clear tribute to his outstanding personal courage. After the War he returned to Melbourne and was admitted to the degree of Doctor of Medicine in 1921. He was appointed to the honorary medical staff of the Melbourne Hospital in 1923 and served until 1948 (his term being interrupted by war service in the Second World War). In the interval between the two World Wars, in addition to practising as a consultant physician, he continued his association with the Army, commanding a field ambulance. He became a divisional surgeon in the St John Ambulance Brigade, commencing a career in the service which took him to its highest office. He played a part in the early days of the Melbourne Permanent Postgraduate Committee and became the honorary secretary.

On the outbreak of the Second World War, Johnston was appointed commanding officer of the 2/2 Australian General Hospital with the rank of colonel. He formed this unit and took it to Egypt. As commanding officer he earned the devotion of all under his command. The ill-fated Greek campaign took him to Greece and Crete where he had the unenviable task of co-ordinating medical services in a rapidly deteriorating situation. He was awarded the CBE in 1942.

On the return of the Australian forces to Australia in 1942, Colonel Johnston was appointed DDMS 1 Australian Corps with the rank of brigadier. He served in New Guinea during the time of heavy malarial casualties and insurmountable difficulties supplying medical stores and evacuating sick and wounded. These exertions told heavily on his reserves of strength and he returned to Australia late in 1942 and was placed on the Reserve of Officers in 1943.

He resumed civilian activities, becoming medical director of the Australian Red Cross Society 1943-44 and a member of the national council of the Australian Red Cross Society from 1945. He continued his association with St John Ambulance and was appointed commissioner for Victoria in 1951, then, six years later, chief commissioner to the Priory in Australia. He was appointed Knight of Grace of the Order of St John of Jerusalem in 1957.

A continuing interest was the Melbourne Medical Postgraduate Committee. He was the director of the Committee from 1947 to 1956 and chairman from 1956 till his death. He was one of the early chairmen of the Australian Postgraduate Federation in Medicine. In his role as chairman of the Melbourne Postgraduate Committee he spent many weekends visiting country centres with teams of lecturers. His support of these activities was greatly appreciated by the centres visited. He was host to many overseas visitors and did everything possible to ease the burden of an overseas tour. Many were entertained at the Melbourne Club, of which he had been a member for many years and had served as president. He was an admirer of Sir Gordon Gordon-Taylor and grateful for Sir Gordon’s help to young Australian surgeons journeying to England. He established the Gordon Taylor Fellowship in memory of this British surgeon.

Johnston was a foundation Fellow of the RACP. He was co-opted to the College council 1949-51 and again 1951-52. He retired from the council in 1952 but was returned to it as vice-president of the College 1958-60 and was a member of the Victorian state committee 1945-62. As the time of his death Sir William Johnston was a member of the council of the University of Melbourne. He had been very active in the Graduate Union of the University and had served as its president. In 1962 the University celebrated the centenary of its medical school and in doing so conferred honorary degrees on a number of distinguished scientists. The degree of Doctor of Laws (honoris causa) was conferred on Sir William Johnston and the acclamation which followed was an indication of the unique place he held in the community, medical and non-medical.

His is an astonishing record of unselfish service. Tall and distinguished in appearance, he was characterised by a courtly grace and dignity which made him welcome wherever he went. The elderly outpatients in his hospital clinic received the same kindly unhurried consideration that was given to the distinguished people who sought his care. Late in his life he was accorded the honour of knighthood, too long delayed in the view of many. He was in truth a ‘Verray parfait gentil knight’.

Dr Johnston married his cousin Jessie, the daughter of Brigadier- General WJ Clark. They had two sons, the elder a graduate in medicine, the younger, after teaching at Melbourne Church of England Grammar School, reading theology at Cambridge and becoming chaplain to MCEGS.

An uncle of Johnston was Donald Wallace, the owner of Carbine, winner of the Melbourne Cup in 1890, carrying the heaviest weight ever by a Melbourne Cup winner. Another uncle was Wilfred Johnston of Craiglee, Victorian Racing Club chief stipendiary steward, after whom the Craiglee Stakes were named. In spite of these racing connections, Sir William was no avid race-goer and had to join the VRC when Lady Johnston was invited as a guest of the Committee on Craiglee Stakes day. Lady Johnston herself was a niece of Alister Clark, the distinguished rosarian, who is commemorated in the Alister Clark Stakes and the Alister Clark Rose Garden in St Kilda.