PS
Peter Salway
Peter Salway, FSA is a British historian, who specialises in Roman Britain. He lectured at the universities of Durham, Cambridge, Bristol and Oxford, before becoming Professor of the History and Archaeology of Roman Britain at the Open University.
Excerpt from Wikipedia, available under CC BY-SA 4.0.
Books

Roman Britain
2000
ISBN 9780192854049
The Frontier People of Roman Britain
2008
ISBN 9780521093156