He was born in Glasgow in 1890, and educated at London university. In 1920, he became director of the National Museum of Wales, Cardiff, and was later keeper of the London Museum from 1926 to 1944. During his career, he carried out many major excavations within Britain, including that of Verulamium St Albans. The methods he used, eg. the grid system, are old-fashioned by today's standards, but were nevertheless effective.
In 1944, he became director-general of archaeology in India, exploring in detail the remains of the Indus Valley Civilisation. On his return in 1948, he was made a professor at the newly-established Institute of Archaeology, and became known through his books and appearances on television and radio, helping to bring archaeology to a mass audience. He was knighted in 1952 for his services to archaeology, and died in 1976.