For a total of seventy-four years in the thirteenth century two women in succession ruled the counties of Flanders and Hainaut. On the death of Count Baldwin ix in crusade in 1206 the powerful fiefdom passed to his six-year-old daughter, Jeanne. Until the imprisonment in 1214 of her first husband, whom she had married in 1212, Jeanne's power was limited but for thirty years until her death in 1244 she exercised not only authority but real power. She was succeeded by her younger sister, Marguerite. Twice married, Marguerite chose to remain a widow throughout her long rule until her retirement in 1278. Erin Jordan's study of these two remarkable women does much to challenge assumptions about how medieval society viewed women who rose to positions of authority and power. She argues that despite changes in inheritance patterns which seemed to favour men, status was more important than gender in establishing authority, and that the real challenge was not the acceptance of female authority but its translation into power. Jeanne and Marguerite emerge as women who were no mere pawns or figureheads for male power or ambition, but women who set their own agenda. The core of Jordan's book lies in the two chapters that deal with the significance of the religious patronage of the countesses. Their voluminous charters for a range of monastic houses (some of them their own foundations, some established by others) reveal the obligation that they, like other rulers, felt to use power derived from God for the benefit of the religious. But there were also social, economic and political benefits that accrued from monastic patronage. Although this idea is not new, Erin Jordan skilfully demonstrates the operation of patronage in a Flemish context: the construction of Cistercian abbeys along the border with France, where treaties had forbidden the erection of castles; the reclamation of land; the large-scale development of pastoral farming; the involvement in the cloth trade. What emerges is the domination of Cistercian houses for women, which were as much engaged as their male counterparts in these activities. The interests of the countesses in Cistercian nunneries may have been gender driven – both women died and were buried in Cistercian nunneries, Marguerite after a two-year retirement there – but in her treatment of spiritual gain, Jordan also draws attention to their firm support of the male mendicants. This is a valuable study, both of female power and of the nature of monastic patronage in a specific context.