For those who ruled medieval society, the family was the crucial social unit, made up of those from whom property and authority were inherited and those to whom it passed. One's kin could be one's closest political and military allies or one's fiercest enemies. While the general term used to describe family members was consanguinei mei, "those of my blood," not all of those relations-parents, siblings, children, distant cousins, maternal relatives, paternal ancestors, and so on-counted as true family in any given time, place, or circumstance. In the early and high Middle Ages, the "family" was a very different group than it is in modern society, and the ways in which medieval men and women conceptualized and structured the family unit changed markedly over time.

Focusing on the Frankish realm between the eighth and twelfth centuries, Constance Brittain Bouchard outlines the operative definitions of "family" in this period when there existed various and flexible ways by which individuals were or were not incorporated into the family group. Even in medieval patriarchal society, women of the aristocracy, who were considered outsiders by their husbands and their husbands' siblings and elders, were never completely marginalized and paradoxically represented the very essence of "family" to their male children.

Bouchard also engages in the ongoing scholarly debate about the nobility around the year 1000, arguing that there was no clear point of transition from amorphous family units to agnatically structured kindred. Instead, she points out that great noble families always privileged the male line of descent, even if most did not establish father-son inheritance until the eleventh or twelfth century. Those of My Blood clarifies the complex meanings of medieval family structure and family consciousness and shows the many ways in which negotiations of power within the noble family can help explain early medieval politics.