A double monastery is a monastery combining separate communities of monks and of nuns, joined in one institution to share one church and other facilities. The practice is believed to have started in the East at the dawn of monasticism. It is considered more common in the monasticism of Eastern Christianity, where it is traceable to the 4th century. In the West the establishment of double monasteries became popular after Columbanus and sprang up in Gaul and in Anglo-Saxon England. Double monasteries were forbidden by the Second Council of Nicaea in 787, though it took many years for the decree to be enforced. Double monasteries were revived again after the 12th century in a significantly different way when a number of religious houses were established on this pattern among Benedictines and possibly the Dominicans. The 14th-century Bridgittines were purposely founded using this form of community.

Æthelthryth was an East Anglian princess, a Fenland and Northumbrian queen and Abbess of Ely. She is an Anglo-Saxon saint, and is also known as Etheldreda or Audrey, especially in religious contexts. She was a daughter of Anna, King of East Anglia, and her siblings were Wendreda and Seaxburh of Ely, both of whom eventually retired from secular life and founded abbeys.