• (1990) Attila and the nomad hordes: warfare on the Eurasian steppes 4th-12th centuries, Osprey Publishing, ISBN 0850459966
• (1991) French Medieval Armies 1000-1300. London: Osprey Publishing, ISBN 1-85532-127-0
• (1992) Arthur and the Anglo-Saxon Wars: Anglo-Celtic Warfare, A.D.410-1066, Osprey Publishing, ISBN 0850455480
• (1993) Armies of the Muslim Conquest Osprey Publishing, ISBN 185532279X
• (1995) Medieval Warfare Source Book: Warfare in Western Christendom, Brockhampton Press, ISBN 1860198899
• (1996) Medieval Warfare Source Book: Christian Europe and its Neighbours, Brockhampton Press, ISBN 1860198619
• (1997) The History of Medieval Life, Hamlyn
• (1998) Crusader Warfare: Muslims, Mongols and the Struggle Against the Crusades, Osprey Publishing, ISBN 1855326973
• (1999) Arms and Armour of the Crusading Era, 1050-1350: Western Europe and the Crusader States, Greenhill Books, ISBN 1853673471
• (2000) Crecy, 1346: Triumph of the Black Prince, Osprey Publishing, ISBN 1855329662
• (2000) French Armies of the Hundred Years War. London: Osprey Publishing, ISBN 1-85532-710-4
• (2002) Warriors and Their Weapons Around the Time of the Crusades: Relationships Between Byzantium, the West and the Islamic World, Ashgate, ISBN 0860788989
• (2004) Poitiers 1356: The Capture of a King, Osprey Publishing, ISBN 1841765163
• (2005) Crecy 1346: Triumph of the Longbow, Greenwood Press, ISBN 0275988430
• (2007) Crusader Castles in Cyprus, Greece and the Aegean 1191-1571, Osprey Publishing, 1841769762
• (2007) Fighting for the Faith: Crusade and Jihad 1000-1500 AD, Pen & Sword Military, ISBN 1844156141

Collaborations

• (2005) with Christopher Gravett: Battles of the Middle Ages, Greenwood Press, ISBN 0275988376
• (2007) with J. Haldon and Stephen Turnbull: Fall of Constantinople: The Ottoman Conquest of Byzantium, Osprey Publishing, ISBN 1846032008

As editor

• (2002) Companion to Medieval Arms and Armour, Boydell Press, ISBN 0851158722