In February 1654, Anne-Marie Martinozzi, a niece of Cardinal Mazarin, married Armand de Bourbon, Prince of Conti. The newlyweds went on to experience almost concurrent pious conversions that would transform their social behavior for the remainder of their lives. Shortly afterward, Armand was posted to northern Italy as commander of the French army, necessitating a six-month estrangement of the couple between May and October 1657. This article explores a corpus of “love letters” penned by the princess during this separation. It argues that Anne-Marie not only claimed to be suffering from “melancholy” as a result of her separation from her lover and spouse, but that she also constructed an image of herself as spiritually lovesick on account of her deprivation from her mentor and confidant. In doing so, this article sheds light on the centrality of copenitents to the direction of spiritual lives in the aftermath of a pious conversion.