Gilbert of Sempringham founded the Gilbertine Order. It was the only English founded order and it was also the only one with double houses. Gilbertine nuns followed the Benedictine pattern whilst the monks followed the Augustinian pattern of canons. Not all houses were double but the one at Watton in East Yorkshire was.
The story was recorded by Ailred of Rievaulx in the early 1160s. Essentially the nun in question was an oblate in that she had been in the priory since she was four years old. Interestingly, the Gilbertines had an age requirement for entry to their order – 24 for men and 20 for women. However, our nun gained admittance as a child at the request of the Bishop of York.
The nun became enamoured of either a lay brother or one of the canons. The attraction was reciprocated. They arranged to meet. The inevitable happened. The nun was found to be pregnant. The nun was beaten and imprisoned and when her lover captured she was forced to castrate him herself. He was returned to the male side of the house at Watton and disappears from the story.
However, the nun returned to her prison, was visited by the now deceased archbishop and two women who took the baby leaving the teenage nun in her original state of virtue. At which point she was allowed out of prison – a miracle having occurred.
It would have to be said that the Gilbertines had strict rules about segregating the canons from the nuns. Nonetheless the priory at Watton which was one of the most important Gilbertine Foundations was said to have many secret passages.
Watton was where Marjory Bruce, the eleven year old daughter of Robert the Bruce, was imprisoned by Edward I in 1306. She regained her freedom after the Battle of Bannockburn.
G. Constable, ‘Aelred of Rievaulx and the Nun of Watton: an episode in the early history of the Gilbertine order’, Medieval women, ed. D. Baker, SCH, subsidia, 1 (1978), 205–26