A cultural historian of the Roman Empire and surrounding regions. Much of his work uses social theory to connect archaeological and historical information about antiquity. He has written on cultural dimension of the expansion of the empire, on Roman imperialism, the Roman economy, and on Roman intellectual culture, and also on iron age hillforts, ancient ethnography and the assasination of Julius Caesar. He has coedited collections on ancient literacy, ancient libraries, encyclopaedic culture in premodern periods, the city of Rome, women in Roman cities and on ancient senses of the self. His latest monograph is Rome. An Empire’s Story. With Jason König at St Andrews he led a Leverhulme project on Science and Empire in the Roman World, and with Jörg Rüpke at Erfurt he leads a collaborative project on sanctuaries and their place in the formation of religious experience and knowledge, funded by an Annaliese Maier research prize from the Humboldt Foundation. He is also writing a book on ancient diasporas and colonization, set in the context of migration theory, and a book on the naturalness of urban life.