In the early seventeenth-century, when Spanish interests often competed with those of the House of Austria, three women in the court of Philip III of Spain--Empress María, Philip's grandmother; Margaret of Austria, Philip's wife; and Margaret of the Cross, Philip's aunt--worked behind the scenes to win favor for the causes of the Austrian Habsburgs. In The Empress, the Queen, and the Nun, historian Magdalena Sánchez offers an intriguing examination of the political power wielded by these three women. Sánchez examines the ways that women used religious piety, childbearing, illnesses such as melancholy, and marriage arrangements to sway political decisions. They employed distinct strategies and languages at informal occasions such as meals, masquerade celebrations, and religious ceremonies to influence the political scene. By incorporating women into informal political networks, this work breaks new ground in the study of early modern European politics.