His specialty is the Classical Mediterranean, especially the Hellenistic World post-Alexander.
He holds an undergraduate degree in history from Oxford University (1978), where he was a member of Balliol College.
[2] His scholarly works include Antigonos the One-Eyed and the Creation of the Hellenic State (1990), Kings and Colonists: Aspects of Macedonian Imperialism (1995)[3] and Marathon - How One Battle Changed Western Civilization (2010).
[4][5] He has taught Columbia's undergraduate survey course in Ancient Greek History.
[4] He also regularly teaches “An Introduction to Contemporary Civilization in the West,” a Columbia College core curriculum class.