  | The Eagle and the Lion: Rome, Persia and an Unwinnable conflict Published by: Head of Zeus (6 July 2023) (UK) Basic Books (5 September 2023) (US) |
  | Philip and Alexander – kings and conquerors Published by: Head of Zeus (3 September 2020) (UK) Basic Books (13 October 2020) (US) |
  | Hadrian's Wall Published by: Head of Zeus (January 2018) (UK) Basic Books (April 2018) (US) |
  | Pax Romana War, peace and conquest in the Roman World Published by: Weidenfeld & Nicolson (Augurst 2016) (UK) Yale University Press (September 2016) (US) |
  | Augustus First Emperor of Rome Published by: Weidenfeld & Nicolson (Augurst 2014) (UK) Yale University Press (August 2014) (US) |
  | Antony and Cleopatra Published by: Weidenfeld & Nicolson (July 2010) (UK) Yale University Press (September 2010) (US) |
  | The Fall Of The West The Death Of The Roman Superpower Published by: Weidenfeld & Nicolson (February 2009) (UK) Yale University Press (May 2009) (US) |
  | Caesar The Life of a Colossus Published by: Weidenfeld & Nicolson (May 2006) (UK) Phoenix (May 2007) (UK) Yale University Press (2006, 2008) (US) |
  | In the Name of Rome The Men who Won the Roman Empire Published by: Weidenfeld & Nicolson (October 2003) Phoenix (August 2004) |
 | The Complete Roman Army Published by: Thames & Hudson (September, 2003) |
  | Cannae Hannibal's Greatest Victory Published by: Weidenfeld Military (December 2001) Phoenix (Maty 2007) |
  | The Punic Wars (Cassell Military Trade Books) Published by: Weidenfeld & Nicolson (September 2000) Phoenix (October 2003) |
  | Roman Warfare Published by: Weidenfeld & Nicolson (February 2000) Phoenix (May 2007) |
 | The Roman Army at War, 100 BC-AD 200 (Oxford Classical Monographs) Published by: Clarendon Press (February 1998) |