In this book, Gabriel Herman offers a new interpretation of Greek xenia, a term traditionally rendered as 'guest-friendship'. Drawing on contemporary literary sources and inscriptions as well as anthropology, sociology, and comparative evidence from other times, he shows that xenia was a bond of fictitious kinship akin to godparenthood, rather than a tie of hospitality or ordinary 'friendship'. Starting off from this proposition, he develops a dynamic model of the formation of elite relationships and values. He explores the concepts of obligation and loyalty, gift and bribe, treason and patriotism, and places the Greek city within a new context of power relations. This book, which assumes no knowledge of Greek, will be of interest to students and teachers of ancient history and classics. It will also appeal to social and political scientists.