Professor of medicine;

Born: June 18, 1926; Died: November 1, 2011.

Lindsay Davidson, who has died aged 85, was an internationally renowned physician who led medical faculties in Rhodesia and Australia and lectured around the world.

He was one of the first intake of doctors on the day the NHS was born – just one of many firsts throughout his long and distinguished career – and counted such diverse individuals as the Queen and Idi Amin among his patients.

Born in Edinburgh, he was educated at George Watson's College and Edinburgh University, graduating MB ChB before taking up his first posts in 1948 as house physician at the capital's Church of Scotland Deaconess Hospital and house surgeon at Edinburgh Royal Infirmary.

The following year he was called up for national service and went into the Royal Army Medical Corps, seeing active service in Kenya and Uganda, where he treated Amin, then a Ugandan army captain.

Back in the NHS in 1951 he worked in West Hartlepool and Durham before going to the Royal Infirmary, Dundee, as a medical registrar. His return to Scotland was short-lived and in 1954 he went to the department of medicine, King's College, University of Durham, as Luccock research fellow.

From there he joined the University of Birmingham and the United Birmingham Hospitals where he became a lecturer in medicine. He had also by this time built up an expertise in cardiopulmonary physiology, gained a doctorate from Birmingham and become a visiting associate in medicine in the cardiopulmonary laboratory of New York's Columbia University.

In 1962 he became the first Scotsman to receive the Rockefeller Travel Grant. That same year he was appointed foundation professor of medicine and head of the department of medicine at the University College of Rhodesia.

In addition he became an honorary professor of medicine at Birmingham University, which sponsored the new Rhodesian medical faculty and awarded its degrees.

He became the first dean of the Rhodesian faculty in 1967 while continuing to practise medicine, as a consultant physician to the Rhodesian Ministry of Health in African and non-African hospitals, and develop clinical and tropical research work.

In 1969 he came back to Scotland as senior visiting research fellow in Glasgow University's bacteriology and immunology department. His next move was to Wales as consultant physician to the University Hospital of Wales and other Welsh teaching hospitals. During seven years in Cardiff he also ran a private practice, chaired the city's British Medical Association division and achieved another first – co-ordinating the first intake of patient's at the University Hospital of Wales.

He was appointed director of the Commonwealth Institute of Health in Sydney, Australia, and professor at the University of Sydney in 1977. There he taught epidemiology, health services research and evaluation, worked as a consultant in thoracic and tropical medicine at the city's Royal North Shore Hospital and was heavily involved with the Australian government's health department as their senior academic and scientific adviser in health services research and policy.

During his time in Australia he was also involved as a consultant to the Royal Flying Doctor service and as project director of the Vietnam Veterans Herbicide Exposure study.

He treated the Queen after coming back to Scotland, to a post as consultant in public health medicine for Greater Glasgow Health Board where his responsibilities included formulating and delivering the board's Good Hearted Glasgow cardiovascular disease prevention programme.

A fellow of the Royal Colleges of Physicians in Edinburgh, London, Australia and Glasgow, his expertise was in demand for lectures and seminars all over the world. His career, which encompassed a large body of research and countless publications, took him to four continents and almost 100 countries.

Despite formally retiring in the 1980s, he continued to work, providing consultancy services until he was in his 70s.

A wise academic who was fair, consistent and honest, his address book was stuffed with contacts for friends and colleagues around the world who could always be relied upon to oblige if he required a medical expert to help someone in need.

A passionate Scot and lover of rugby, who was once capped for Scotland in a match against Uganda, he was also generous, persuasive and courteous.

Renowned for being a complete gentleman, that trait was never more in evidence than latterly in Carmarthen when he became a patient himself. True to type, he was immaculately turned out, handkerchief in his top pyjama pocket and perfectly charming to the ward team.

Divorced from his first wife, he is survived by Gillian, his wife of 36 years, and his children Jane, Gavin and Claire.