Since the mid-1990s the study of medieval masculinity (understood as plural and situationally constructed) has become an important subset of medieval studies. Several collections of essays on the subject have been published, allowing us to move on from treating medieval men as a monolithic, unvarying other, and from assuming that either masculinity or femininity were always constructed in opposition to each other, comprehending gender identities instead as occupying a spectrum of possibilities rather than a simple binary. Given the heightened profile of medieval masculinity within medieval studies it is perhaps surprising that Ruth Mazo Karras's book constitutes the first single-authored study of this subject. Karras is a well-established authority on issues of medieval sexuality and gender and her book is an extremely welcome addition to the debate. She begins by stating that ‘Medieval Europe was a man's world’ (p. 1) and sets out to unpick the patriarchal nature of medieval society by noting that ‘not all men were in the same position in terms of their power and influence, or in terms of the way society viewed them as gendered beings’ (p. 1). She therefore emphasizes the crucial link which existed between gender and power, or, more specifically, between certain brands of hegemonic masculinity and social power.