[2][3][4] Mærwynn was the founding abbess of the reconsecrated Abbey of Romsey, and there is some certainty that she was appointed to the position by King Edgar the Peaceable on Christmas in 974.
[5] While medieval legend had it that she was born in Ireland and educated by St. Patrick, historical understanding that five centuries separate them discounts this.
[6] She is instead known more historically from several surviving documents: a king's charter, by Edgar the Peaceable, to Romsey Abbey; the medieval confraternity book of Winchester, known as the Liber Vitae of the New Minster;[7] and the Secgan manuscript's hagiography.
[6] King Edgar sent Ælfflæd, his daughter,[8][9] to Mærwynn for care, and she became like a foster mother to the princess.
[10][11] The foundations of Mærwynn's abbey have been located under the tower, choir stalls and part of the nave of the current Norman church.