Title: Regina
Description: During her lifetime, Berenguela of Castile exercised every kind of queenly authority: as her father's heir in Castile, as wife to the king of neighboring León, as regent for her younger brother, as a reigning queen in her own right, and as queen-mother during the reign of her son. This dissertation, the first full-length study of Berenguela's career, demonstrates that her unprecedented authority was based in her control of a strategically vital region known as the Tierra de Campos, on the border between the kingdoms of León and Castile. Using the period's surviving documentation--such as chronicles, royal diplomas, and private charters--the dissertation defines an original, quantitative methodology to reconstruct how Berenguela distributed the tenancies of her personal properties. Analysis of Berenguela's patronage network reveals that the nobles to whom she awarded tenancies were almost exclusively members of families whose own properties were located in the Tierra de Campos. Their support enabled Berenguela to parlay her lordship in this region into dominance in the kingdoms of both León and Castile. Even her best-known achievements--the coronation of her son Fernando III as king of Castile, and the union of the kingdoms of Castile and León--were accomplished through the skillful mobilization of her resources and allies in the Tierra de Campos. In establishing Fernando III as king of Castile and León, Berenguela forged an extraordinary partnership with him. The functions of that partnership, documented here, demand a reconsideration of the role of the "queen-regnant" and expand current understanding of the ways in which medieval men and women shared power.

These findings also shed new light on relations between monarchy and nobility in thirteenth-century Iberia, and provide the field of medieval queenship studies with fresh insights into the methods used by royal women to establish, protect, and expand their power.