Sor María de Santo Domingo was a Castilian tertiary who rose to prominence at the beginning of the sixteenth century. Born and raised in Aldeanueva, Ávila, where the Duke of Alba sponsored the foundation of a lavish convent where she served as its first prioress, Sor María became one of the most influential mystics in her order at the time. Her trances, stigmata, fasts, and role as the reformer of her order aroused admiration from her supporters but acute suspicion from her detractors, who managed to summon four investigations on her visionary life and anomalous behaviors. To document her visionary life, Las revelaciones de Sor María de Santo Domingo and El libro de la oración de Sor María de Santo Domingo were composed by her confessor. Sor María was never sentenced in her trials, and she was labeled as a religious model. Her two works, written by her confessor, are the first mystical treatises written in Spain in which the voice of a woman can be heard and that express the transmission of nonwritten culture.