* The Manuscript (1998)
* Platoon (2001)
* The Last Legionary (2002)
* The Emperor's Legion (2003)
* The Eagle's Shadow (2004)
* The Iron Hand of Mars (2006)
* Julian's Falcons (2008)
* Belisarius: the Last Roman General (2011)
* Attila: the Last Nomad (2015)
* Genghis Khan: the Conqueror of the World (2017)
* Saladin: the Sultan of Egypt and Syria (2019)
Non-fiction:
* The Roman Army (2002)
* The Roman Empire (2004)
* The Ancient World (2006)
* The Classical World (2008)
* The World of the Ancient Greeks (2010)
* The World of the Ancient Romans (2012)
* The Ancient World: A History (2015)
* The Roman Empire: A History (2017)