Berlin Opera House, where Agnes was immortalized
via Wikimedia Commons
Agnes of Hohenstaufen pleaded with her mother, Irmengard of Henneberg, to help her escape this plight and fortunately for her, her tears fell on a tender heart. Irmengard waited for her husband to leave town before sneaking Henry of Guelph into the castle to secretly marry Agnes.
When the Emperor found out, he was enraged. He commanded that the marriage be annuled. This time, however, Agnes's father stood up for his daughter and turned lemons into lemonade. He convinced the Emperor that this marriage between a Guelph and a Hohenstauffen could end years of dynastic rivalry. Soon, the Emperor was reconciled with Agnes's new father-in-law and internal peace returned to the Holy Roman Empire. Young Henry became the heir of his new father-in-law, and they all lived happily ever after (in a 12 century sort of way).
This true story went on to inspire a 19th century Romantic opera, Agnes von Hohenstaufen, about a young girl's battle to marry the man of her own choosing. Written by Italian composer, Gaspare Spontini, it premiered in Berlin in 1829.
The opera Agnes von Hohenstaufen:
Download the aria, O re dei cieli, sung by either Anita Cerquetti:
O re dei cieli from Agnes von Hohenstaufen, aria sung by Anita Cerquetti: