Early medieval and Viking era (800-1166)

Early Medieval Italy: Central Power and Local Society 400-1000.

Early Medieval Ireland, 400-1200, London and New York, 1995.

Early Medieval Europe 300-1000, 2nd edition.

Early Medieval Europe 5 (1996) 155-175.

Early Medieval Europe 15 (2007), 186-222.

Early Medieval Europe 17 (2009), 389-419.

Early medieval law-tracts set out five types of road:

Early medieval Italy: central power and local society, 400-1000 (1981)