Petrus de Dacia was performed for the last time in the romantic St. Nicolai church ruin in Visby on the 10 August 1990, and under the trademark "Ruinspelet" was the Gotlandic summer vacation's musical highpoint for thousands of visitors from all over the world, for over 50 years. Even though the composer, conductor and director Friedrich Mehler, purely on a confessional basis, avoided the operatic label on his artistic life's works, it can now, 30 years after the originator's death and 753 performances, surely be considered the most performed Swedish opera of all time.