St Etheldreda (c. 636–679) was an Anglo-Saxon princess, abbess, and one of the most influential female saints of early medieval England. She is best known as the foundress of Ely Abbey, which later developed into Ely Cathedral, and as a model of royal sanctity grounded in asceticism and monastic leadership.

Born into the ruling house of East Anglia as the daughter of King Anna, Etheldreda entered two politically motivated marriages, first to Tondberht, ealdorman of the South Gyrwe, and later to King Ecgfrith of Northumbria. According to early sources, she maintained a vow of chastity throughout both marriages. After securing Ecgfrith’s consent, she withdrew from secular life and embraced the religious vocation.

Around 673 she founded a double monastery for men and women at Ely, where she ruled as abbess. Her governance combined royal authority with monastic discipline, and Ely quickly became an important religious centre in eastern England. She died in 679, probably of plague.

Sixteen years after her death, her body was translated and reportedly found to be incorrupt, an event that firmly established her cult. Ely became one of the principal pilgrimage destinations of Anglo-Saxon England, and devotion to St Etheldreda spread widely through East Anglia and beyond.

In art, St Etheldredaa is most commonly depicted as an abbess or crowned royal saint. Her attributes often include a crozier or abbess’s staff, and a model of a church symbolising the foundation of Ely. In later medieval and post-medieval stained glass she frequently appears as a local or diocesan patron, especially in churches with historic links to Ely.