Cartas de la monja portuguesa

It is a 17th-century epistolary theater classic depicting unrequited love. Written by an anonymous author, the work portrays Sor Mariana—cloistered in a Portuguese convent—as she pens five letters of love and passion to her absent French lover. Sorrow and despair consume this nun who, though wedded to God, is unfaithful in her obsession with the foreign officer. A longing for profane love and a descent into madness overtake her as the years pass inexorably until her death.