Regine

Lohengrin:

In a time of great turmoil in Brabant, a young noblewoman Elsa is sentenced to death for murder. She denies the allegations and awaits a champion who might represent her in a duel. A knight abroad a swan boat appears. He is a divine warrior sent by God to end the region's strife and to preserve her honor. He defeats her accusers without killing them and vows to restore balance to the region so long as no one--especially the young woman--has knowledge of his identity. 

Unfortunately, the pagan usurpers who caused the disruption in Brabant continue to plot after their initial defeat. They sow the seeds of doubt within Elsa to try and get her to reveal the knight's identity. Finally, just before they are about to be married, Elsa is overcome with curiousity and discovers that the knight is actually Grail Knight Lohengrin. Once his identity is known, the knight is compelled to leave. Before doing so, he returns the swan to it's original form: Elsa's missing brother Gottfried. Sadly, as the knight leaves, Elsa drops dead from sadness.

Lohengrin is an opera written by Wagner that was originally performed in the mid-1800s.