Robert Campbell Begg was born on 11 April 1886 in Dunedin, the son of Katherine Clarke and her husband, Alexander Campbell Begg, an accountant. He attended Kaikorai School, and then Otago Boys’ High School from 1898 to 1901, before working in an office. Begg’s Presbyterian upbringing directed him towards a life in the church, and he studied at the University of Otago, graduating MA in 1907 and BSc in 1908. However, influenced by his elder brother, Charles, Campbell instead decided to pursue a career in medicine, and in December 1907 he left New Zealand for the University of Edinburgh. He qualified MRCS and LRCP in 1911. After a brief return to New Zealand, where he worked as a locum, he was employed as a house surgeon at the Royal Infirmary, Edinburgh.
Begg then took up a position as a medical officer with Barnato Consolidated Mines in the Transvaal from 1912 to 1914. With the outbreak of the First World War he joined the Red Cross, treating Indian troops in Flanders. In 1915 he was posted to the Royal Army Medical Corps in Egypt, where he attended to casualties from Gallipoli. The next year he was sent to Mesopotamia, becoming medical officer to No 20 British Field Ambulance. He had to cope with appalling conditions: disease was rife, supplies were short, and Arab raids threatened. Begg himself survived influenza and a bite from a rabid dog. He was awarded the Military Cross in 1917.
After the war Campbell Begg set up a general practice on Willis Street, Wellington. On 28 January 1920 in Wellington he married Joan Angela Carlisle Kendall; they were to have five children. Campbell wished to specialise in urology, and in 1923 he left for Edinburgh, where that year he became MD and FRCS. On his return to New Zealand he was appointed urologist at Wellington Hospital. He wrote several papers on the subject, and in 1927 was a foundation fellow of the College of Surgeons of Australasia. That year he also visited America, attending the prestigious Mayo clinic. In 1930 Begg went on a tour of America and Europe, where he flew on the airship Graf Zeppelin. This was the start of his enthusiasm for flying.
In 1931 Campbell Begg was a controversial candidate for the Wellington Hospital Board. He conducted a high-profile campaign, railing against inefficient hospital administration and demanding cuts to social services expenditure; he topped the poll. His proposals for radical hospital reform, advocating the abolition of the 45 hospital boards and their replacement by 18 districts, brought strong opposition from other hospital boards, but much of his scheme for hospital reorganisation was adopted by the 1932 National Expenditure Commission. His campaign against inefficiencies in hospital administration drew him inevitably into national politics, and in February 1933 he was appointed president of the New Zealand Legion, a conservative political reform movement opposed to party politics and the growth of state bureaucracy. Begg appeared to be the ideal leader: tall, dignified, with forthright opinions. However, he was a poor orator and seemed uneasy in the rough and tumble of politics. On the public platform he would only answer written questions. When heckled, he was irritable and slow to respond. Later, he wrote, 'I certainly didn’t know what I was letting myself in for’.
Nevertheless, Begg threw himself into the leadership of the Legion, attending 42 meetings around the country in five weeks and calling on New Zealanders to 'make any necessary personal sacrifice for the sake of the country’. Initially the Legion flourished; its vague appeals to patriotism and old-fashioned individualism met with an enthusiastic response at a time when New Zealand was mired in depression, and about 2,000 people joined in the first month. Begg was critical of New Zealand’s sectional divisions and dependence on Britain, and his appeals for self-reliance, national unity and public morality found sympathy with conservative voters disillusioned with the Forbes–Coates government. The Legion articulated the frustration of conservative, small-town New Zealand at the depression and the ineffectiveness of traditional parties. Although it was reviled by the left as fascist, its hostility to 'State paternalism’ had little in common with fascism. Nevertheless, without policy and organisation, the Legion could not be sustained. Initial enthusiasm waned; although membership peaked at 20,000 in late 1933, by the end of 1934 the organisation was practically extinct.
In 1936 Begg went on another world tour, during which he was wooed by the Nazis, but he found Nazism absurd. In 1937 he and his family moved to South Africa. There he established himself as a leading surgeon, becoming president of the Afrikaans Medical Society in 1951. After his retirement from surgery in 1956, he continued to travel and fly, and he wrote three memoirs. A somewhat aloof man of great integrity, Campbell Begg died on 26 July 1971 at Johannesburg, survived by his five children.