Thomas Barfield is a social anthropologist who conducted extensive ethnographic fieldwork among pastoral nomads in northern Afghanistan in the mid 1970s and shorter periods of research in Xinjiang, China and post-Soviet Central Asia. He is the author of The Central Asian Arabs of Afghanistan (1981), The Perilous Frontier: Nomadic Empires and China (1989) and Afghanistan: An Atlas of Indigenous Domestic Architecture (1991). After 2001 his research returned to Afghanistan, focusing on law, government organization and economic development issues on which he has written extensively. In 2006 he was awarded a Guggenheim Fellowship that led to the publication of Afghanistan: A cultural and political history (2010), a book that received an outstanding title award for American Library Association in 2011. He has served as President of the American Institute for Afghanistan Studies since 2005. His forthcoming book, Shadow Empires, explores how distinctly different types empires arose and sustained themselves as the dominant polities of Eurasia and North Africa for 2500 years before disappearing in the 20th century.