'A voracious reader, admirer of drama, and ardent critic, he is a mine of information often of doubtful accuracy. Always interesting...an excellent companion.'

So states the University of Sydney's Faculty of Medicine Year Book for 1936, of the 'innocent rosy-cheeked product of Blue Mountains', and except for the mature development of an obsession for accuracy, it remained true of the older man. To be found 'where the good things of life are to be found', John Cobley's boundless enthusiasm for life animated any conversation, which might range over many topics; European history, English literature and exploration (almost anywhere, but essentially to the Antarctic) were amongst his many later interests. Notes he made on his wide reading at one period reflect his critical but eclectic approach; he accepted no authority's generalisation but sought out the sources to form his own appraisal. A sceptical wit often enlightened forthright comment on people and events, barely perceptibly more so with the inevitable association of a well selected wine from his cellar.

John Cobley was born on 3 August 1914; his father was a mine administrator at Abermain and later an estate agent at Leura. From Katoomba High School he obtained a scholarship to the University of Sydney graduating in Medicine in 1937, having served St. Paul's College well in the intercollegiate boat races. His first appointment was as a ship's surgeon to England, where he did a variety of house physician jobs, notably in neurology and cardiology, in London and elsewhere. After one or two unsuccessful attempts he obtained the senior qualification of membership of the Royal College of Physicians of London, as well as a diploma in anaesthesia; after the war he became a member of the Australasian College. He returned to Australia, again as ship's surgeon; war was declared during the voyage.

Until commissioned in July 1940, he was tutor in medicine at St. Paul's and other colleges, while also doing physicianly tasks at the University, Sydney hospital and privately in Macquarie Street. Captain, later Major, Cobley served successfully with 2/3 Casualty Clearing Stations, 2/8 Field Ambulance, 111 Casualty Clearing Station in Greece, Syria, at El Alamein and in New Guinea. On leave as the war ended, he was then with 113 Military Hospital at Concord until discharged in February 1946. He continued in the Citizen Military Forces after the war, reaching the rank of Lieut-Colonel, commanding 1 Field Ambulance. He was mentioned in despatches, probably for work on scrub typhus, which included the unpleasant task of walks in the jungle to collect the disease-transmitting mites. Two medical papers were published from a very varied clinical wartime experience. He remained active in Legacy for many years.

While on leave after returning from the Middle East in 1943, John married Margaret Sanbrook, daughter of a Sydney general practitioner, whom he had met in London before the War. Then a private in the Australian Women's Army Service, she was to make an admirable lieutenant to John in all his subsequent activities, particularly in relation to his historical research but not less as a superb hostess to their multitude of friends.

The immediate post-war period was a disappointing one for John, when probably because of a personality clash with a senior medical administrator, he failed to obtain appointment as an honorary physician to a teaching hospital. This limited his opportunity to develop private practice as a physician, although he later held various appointments at the Royal Women's hospital, in the Diabetic Clinic at Royal Prince Alfred hospital and as a consultant physician to the Repatriation Department. General practice, at Fairlight (Sydney) until 1965 was frustrating; in his words, 'I hated it chiefly on the grounds that none of my training and experience had been directed that way'. From 1957 to 1960, he was a member of the Council of the British Medical Association (New South Wales branch).

From 1966, as 'Dr. John', he conducted Casebook for Channel 7 for two and a half years, work which was suited to his personality and his capacity for lucid expression; he wrote the scripts himself but declined to provide enough 'drama, blood and guts' to suit his employers. There were many who regretted its cessation, not least John, but it did provide the funds for historical research in England. By this time, stimulated initially by a daughter's school project, he had become involved in the elucidation of the history of Sydney Cove and its first European occupants. He read widely and sought advice and help from a number of distinguished historians before deciding simply to record the events in the settlement day by day in the words of the writers of the time. Between 1962 and 1986, he published the series of works covering the period 1788 to 1800. The material for the first volume was collected only to satisfy his curiosity, without thought of publication, but a Hodder and Stoughton representative from London, introduced by a patient, saw the material and wanted to publish it immediately. The family set to work to put it into publishable form but inexperience led to innumerable corrections in proof. The book thus appeared at a considerable financial loss. At one stage he planned to continue until the establishment of the Sydney Gazette in 1803, but the sources became few and the challenge loss.

When Lloyd Robson published his pioneering statistical study 'The Convict Settlers of Australia' (1965), Cobley published the equally original 'The Crimes of the First Fleet Convicts', as well as a detailed study of a one in twenty sample of a larger series, 'The Convicts 1788 - 1792'. In their different ways, these seminal works introduced a new dimension and new techniques to Australian historiography, although John's acknowledgement to A.J. Gray should not be overlooked. A quarter of a century later, it is interesting to recall that there was official opposition to his using the convict names, resolved only by a personal appeal to Mr Justice Evatt. This was successful less on the grounds of logic, in John's view, than on the fact that the learned judge had known his father. As Sandy Yarwood has observed, no one else did so much to popularise Australian history. All but the most recent of his books have been republished, and his decision to attempt no more than to reproduce original material precisely as it was written, avoiding an interpretation, ensures their lasting value. Although delighted by the elegant re-issue of 'Sydney Cove 1788' in 1987, he was not a little concerned that some of the illustrations were of a later date, a reflection of his concern for historical authenticity.

From 1970, after his father's death, John and Margaret Cobley came to spend more of their time at the family home at Leura. In 1975 he relinquished his Macquarie Street practice on appointment as staff physician to the nearby Blue Mountains District Anzac Memorial hospital. That he was a humanistic and alert physician, with an eye for a rarity, I can attest from cases that he referred to me or that I asked him to see. In 1980, he was not re-appointed, partly because, in his view, he declined to expand the outpatients department at the expense of the conventional ethical procedure of referring inpatients back to their own general practitioners. He and his wife celebrated this event with a bottle of champagne and a holiday. What is most important about this period and subsequently is that the Cobley home became a focal point for entertainment (not that it had not always been so); the teamwork of John and Margaret in producing wonderful food, fine wine and good company will long be remembered. Here too were welcomed many people seeking advice on matters historical.

I first met John in the 1950s, but neither of us recalls how or why. What I do remember is the joy of collaborating with him in our joint study of the health problems of the first settlement at Sydney Cove. He was meticulous in tracing each convict who died to the ship or the likely ship of arrival. He tested critically each hypothesis as to the cause of mortality, and especially against his remarkable memory (and index cards) of what was known of every name. It is but fair to record that although we finally agreed as to the probable causation of the striking but strange mortality amongst Third Fleet personnel after its arrival, he argued plausibly, if not conclusively, for tuberculosis as a possibility. For his last work, 'The Lady Juliana Convicts - 1790', the research was undertaken chiefly by correspondence when a plan for a further visit to England did not mature. He corrected the final typescript; prepared by a daughter, in the early stages of his last illness; all his previous books were typed by Margaret with two or three fingers.

In 1936, John Cobley's contemporaries observed that a few months of the medical course saw "the unfolding of a personality till then dormant", a person who saw work not as "an opiate but as a stimulant". Those who knew him in later life, especially at the University Club or the Sydney Cricket Ground, will have difficulty in recognising him as ever the possessor of a dormant personality, but his life did indicate a facility for responding to all life's stimuli, many of which others might ignore. John believed that life was to enjoy but that there was a responsibility to contribute. He is survived by Margaret, three daughters and seven grandchildren.