Complex sentence: From 1946 to 1953 he was a lecturer at the London School of Economics (LSE), from 1953 to 1958 at Queen Mary, University of London (then called Queen Mary College).
Split into simpler sentences: From 1946 to 1953 he was Lecturer at the London School of Economics. From 1953 to 1958 he lectured at Queen Mary, University of London (then Queen Mary College).