Mariana of Austria (1634–96) was Philippe IV's wife and niece, and, as such, reigned as queen-consort of Spain from 1649 until his passing in 1665. Subsequently, she served as regent for her minor son, Charles II (b. 1661, r. 1665–1700), until 1675, afterward as an informal counselor. Mariana and Charles II are traditionally associated with Spain's decline. Their era marked the end of the Habsburg dynasty, which would be replaced by the Bourbons, and, therefore, the end of the empire created by Charles V and his successors. Mitchell's study does not see decadence in Mariana's and Charles's reigns, and considers the latter a fully functioning monarch, although he is only discussed in passing because the book is about his mother. This volume reassesses Mariana's ten-year regency. In Mitchell's words: “based on new sources and a reinterpretation of known ones, this monograph seeks to establish Mariana's rightful, preeminent place in Spanish history, a place denied to her for nearly three hundred years” (5). Thus, this volume looks at seventeenth-century Spanish and European politics from the perspective of the queen who, as regent, shaped the politics of the time—“a dynamic period of economic, demographic, diplomatic, and political transformation” (7).

Mariana should not be seen as an anomaly: she is part of a long tradition of medieval and early modern Iberian royal women who actively participated in government as queens in their own right, as well as lieutenants, regents, and viceroys. She was the daughter of Ferdinand of Styria and Maria of Austria, monarchs of Hungary and Bohemia and Holy Roman emperors. After an introduction, the book is structured in seven chapters and a conclusion. Chapter 1 addresses Mariana's early life, from birth to the beginning of her regency. During this period, she got married, had five pregnancies and several miscarriages, and gave birth to two children who reached adulthood. Her first, Margarita Maria (1651), married Emperor Ferdinand, who was Mariana's brother and Philip IV's nephew. Her second, who would go on to reign as Charles II, was born in 1661. Mariana's transition from queen-consort to dowager, queen-mother, and regent was facilitated by Philip IV's last will and testament in which he named Mariana “tutor and curator” (54) for Charles and “governor” (55) during his minority. In this capacity she needed to collaborate with the royal councils and the Junta de Gobierno (Regency Council), which was composed by the presidents of the Councils of Castile and Aragon, the archbishop of Toledo, the Inquisitor General, and a grandee. Her shift from queen consort to regent dowager was reflected dramatically in her physical appearance. She went from wearing sumptuous outfits and hairdos, beautifully portrayed by Diego de Velazquez, to a more modest nun-like attire that dignified her role.

Chapters 2–5 assess her regency, with a particular emphasis on international politics, including her unsuccessful efforts to recover Portugal and her crucial diplomatic work to recruit Emperor Ferdinand to support her polices in the Spanish Netherlands and against France. Also important were the marital arrangements she made for her children. Chapter 6 discusses the emancipation of Charles II at fourteen, a development that Mariana unsuccessfully tried to delay for two years. This resulted in what was effectively her exile from the court, and paved the way for the ascent of Mariana's cousin and illegitimate stepson, Juan of Austria, whose ambitions she had curtailed until then. The final chapter covers the years 1678–79 and examines Mariana's reconciliation with her son through correspondence, her rehabilitation, and, finally, her return to court. This chapter is of particular interest because the queen's own voice is finally heard through excerpts from her letters (which, disappointingly, are only included in English translation). Although the book is based on extensive archival research this is hard for the reader to appreciate: Mitchell does not discuss the nature or limitations of the sources, and there are very few excerpts (always in translation) and only very brief endnotes. A theme that runs through the book is how power worked, who held it and why, and how it was negotiated. As was customary in the period, Mariana worked with councils and royal favorites, but in her case this was particularly challenging, given the resistance she received and the competition these validos faced at court.

In sum, Mitchell's portrayal of Mariana as a successful regent who took some missteps but who nevertheless changed “the course of Spanish history” (232) is not only very convincing, but also most welcome. This is a book that specialists and graduate students working on gender, power, and early modern European politics will find very useful.