"Don Giovanni" is based on a character in European folklore. This character is known as Don Juan. In 1581, the first play about Don Juan was written in Spanish by Juan de la Cueva. Other plays were also written. The most famous Don Juan play was "The Playboy of Seville and His Stone Guest" by a Spanish monk named Tirso de Molina. This play is the source of all the Don Juan stories and plays that were written after it. Da Ponte even used some words from it when he was writing "Don Giovanni".