In 1934 he joined the British Museum as Assistant Keeper in the Department of Egyptian and Assyrian Antiquities. He published Hieroglyphic Texts for Egyptian Stellae. in 1939. During World War II he was sent to Egypt on military duty. In 1946 he wrote The Pyramids of Egypt, which was published by Penguin Books in 1947. In 1955 he was appointed the Keeper of Egyptian Antiquities at the British Museum and organized the Tutankhamun exhibition in 1972. He remained there until his retirement in 1974.
On leaving the British Museum he worked with UNESCO during the rescue of the temple complex at Philae. He was also Vice-President of the Egypt Exploration Society, a Fellow of the British Academy (1962) and was awarded the CBE in 1968 for his services to the British Museum.