The first four studies in this volume by Jean-Claude Cheynet, specially translated from French for publication here, present a broad-ranging analysis of the Byzantine aristocracy of the 8th-12th centuries. Along with the other articles in the first part, they examine the evolution of aristocratic families and the composition of this group, the relative importance of landholding and public office, the notion of ''civilian'' and ''military'' families, and patterns of inheritance. In the second part, the focus is on the Byzantine army, with studies looking both at the position of aristocrats within it, and more generally at the effectiveness of the army itself, notably in the campaigns in Asia Minor against the Arabs and the Turks.