Wikipedia
Saint Cuthburh or Cuthburg (died circa 718) was the first Abbess of Wimborne Minster. She was the sister of Ine, King of Wessex and was married to the Northumbrian king Aldfrith.
King Osred was Cuthburh's son; whether King Osric, and the Offa killed in Eadberht's reign, were also her sons is less certain.
According to a report by " Florence of Worcester", writing long afterwards, at some time before Aldfrith's death in 705 he and Cuthburh "renounced connubial intercourse for the love of God." Following this, Cuthburh entered Abbess Hildelith's nunnery at Barking Abbey. The dedication of Aldhelm's treatise De virginitate includes Cuthburh, who was then at Barking; it is thought that she was in some way related to Aldhelm. After Aldfrith's death, Cuthburh and Cwenburh established a double-monastery in her brother's kingdom of Wessex, at Wimborne, Dorset.
She is described as austere, and she communicated with prelates through a little hatch in the nunnery at Wimborne. Among Saint Boniface's surviving letters is an anonymous account of a vision of Abbess Cuthburh in hell. The feast day associated with her is 31 August. No early hagiography, composed before Norman Conquest, is known to survive.