(1992) Medieval Military Technology Broadview Press.
(1999) Joan of Arc: A Military Leader Gloucestershire: Sutton Publishing, ISBN 0-7509-1805-5
(1999) The Norwegian Invasion of England in 1066 Boydell Press, ISBN 1-84383-027-2.
(2000) Infantry Warfare in the Early Fourteenth Century Boydell Press.
Guns and Men in Medieval Europe
(2002) A Cumulative Bibliography of Medieval Military History and Technology History of Warfare, Vol. 8, Brill Press.
(2002) The Battle of the Golden Spurs : Courtrai, 11 July 1302 Boydell Press.
(2005) A Cumulative Bibliography of Medieval Military History and Technology: Update 2004 History of Warfare, Vol. 26, Brill Press
(2005) The Artillery of the Dukes of Burgundy 1363-1477 Boydell Press.
Collaborations
with Matthew Bennett, Jim Bradbury, Ian Dickie and Phyllis Jestice: (2005) Fighting Techniques of the Medieval World: AD 500-AD 1500, Amber Books, ISBN 1862272999