Returning to Britain, he obtained his doctorate from UCL before taking on a position at the National Museum of Wales, first as Keeper of Archaeology and then as Director, during which time he oversaw excavation at the Roman forts of Segontium, Y Gaer, and Isca Augusta with the aid of his first wife, Tessa Wheeler. Influenced by the archaeologist Augustus Pitt Rivers, Wheeler argued that excavation and the recording of stratigraphic context required an increasingly scientific and methodical approach, developing the "Wheeler method". In 1926, he was appointed Keeper of the London Museum; there, he oversaw a reorganisation of the collection, successfully lobbied for increased funding, and began lecturing at UCL.