La Celestina by Fernando de Rojas, translated and edited by Ashton Lackey

In 1499, an anonymous 16-act play was published in the Spanish town of Burgos that influenced the flourishing of the Spanish language and literature. Known as the La Comedia of Calisto and Melibea, it became widely popular. As a result, other editions were published in the next three years. A second edition came off the press in 1500, and a third edition was printed in 1502. In this 1502 edition, readers could put a name to the author—Fernando de Rojas—who added five more acts with an introduction and concluding material. The title was then changed to the La Tragicomedia de Calisto y Melibea, but this masterpiece later became known simply as La Celestina—the name of the cunning and seducing protagonist.
Calisto, a young nobleman, sees Melibea and falls head-over-heels in love. However, Melibea rejects him. Calisto enlists Celestina, an old woman who has seen and done it all, to help him win over the fair young lady. Celestina is successful, but the costs are high. By the end there has been a murder, a suicide, a more-or-less accidental death, and two characters have been beheaded for their actions.