Arthur Duncan Gardner was born on 28 March 1884 at Rugeley, Staffordshire. He was educated at Rugby School, University College, Oxford, and St Thomas's Hospital. He had a distinguished academic and athletic career. As an undergraduate he read law and represented Oxford at hockey. Changing to medicine, he qualified in 1911 and in the following year obtained the FRCS. At St Thomas's he won the Hadden and Beaney Prizes, and was a lecturer in pathology. At Oxford he was elected to the Radcliffe Travelling Fellowship in 1914 and in 1923 was awarded the Radcliffe Prize for medical research. During the first world war he was a surgeon with the Red Cross in France. His main life's work was in two subjects, bacteriology and administration. He was in turn lecturer, reader and Professor of Bacteriology at Oxford. From 1915 to 1936 he was director of the Medical Research Council's standards laboratory. He did important work on the antigenic properties of the cholera vibrio and Haemophilus pertussis, which led to greatly improved vaccines for cholera and whooping cough. He handled the bacteriological side of the early work by Florey and Chain on penicillin. As well as numerous papers, he published a book on microbes and ultramicrobes and a successful textbook *Bacteriology for medical students and practitioners*, which reached its fourth edition in 1953. In 1948 he made a complete change in his career when he became Regius Professor of Medicine, a post which he held for six years. He was confronted with many problems arising from the aftermath of war, the question of the continuation of the clinical school, the advent of the NHS, and the relationship of the university to the hospitals and the health service. These he faced with equanimity, sound judgement, and a capacity to smooth agitated personalities. He left the clinical school in a much better state than he found it. An honorary fellowship at his old college gave him pleasure. He was Rede lecturer at Cambridge and Litchfield lecturer at Oxford. Gardner was a many-sided man of great charm, but a kind and gentle exterior covered decided views. Although a dedicated scientist, he could recite more of Shakespeare and Milton than most of us. He was modest almost to a fault. Interested in everything, he once remarked that if he were young again he would certainly volunteer to go to the moon. A delightful sense of humour, unobtrusive kindnesses, and generous hospitality were other endearing traits. He married Miss Violet Newsam and had three children, two of whom predeceased him. His surviving son is a surgeon at Torquay. He died on 28 January 1978 aged 93 years.