 In 1931, at the age of 24, he became a lecturer at the University of Durham, "already with an impressive record of excavation on Hadrian's Wall, partly under the guidance of F.G. Simpson," whom he would replace upon the latter's stepping down as Director of Field Studies.Through trips to Germany and Switzerland, he began to expand his expertise in samian pottery, epigraphy, and his primary field of interest, the Roman army.As a consequence of these trips abroad, his continental reputation grew.