In what year was the abbess who wrote the biography of Bertha of Bingen born?
Bertha of Bingen Saint Bertha of Bingen (German: "Heilige Berta", died ca. 757) was the mother of Rupert of Bingen. Her biography was written, and subsequently her cult popularized, by Hildegard of Bingen, who lived in the same region, about three hundred years later. Bertha and Rupert share a feast day on May 15.
Gisela of Kerzenbroeck Gisela of Kerzenbroeck or Gisela von Kerssenbrock (died by 1300) was a nun in the northern German city of Rulle who probably worked most of her life writing and illustrating manuscripts, as well as being choirmistress.