51°03′39″N 1°18′34″W / 51.0608°N 1.3095°WSt. Mary's Abbey, also known as the Nunnaminster, was a Benedictine nunnery in Winchester, Hampshire, England. It was founded between 899 and 902 by Alfred the Great's widow Ealhswith, who was described as the 'builder' of the Nunnaminster in the New Minster Liber Vitae. The first buildings were completed by their son, Edward the Elder. Among the house's early members was Edward's daughter Edburga.
Sometime after 963 Bishop Æthelwold re-founded the monastery and re-endowed it, imposing the stricter Benedictine rule. According to Æthelwold's hagiographer, Wulfstan the Cantor, Æthelwold made a woman called Æthelthryth abbess of the Nunnaminster. Æthelwold may also have translated the relics of Edburga, now recognized as a saint, to a more prominent shrine within the Nunnaminster; however, this event is only attested in Osbert of Clare's much later Vita S. Edburgae.
