),[2] her date of birth and death are controversial), also known as Adelheid, was the abbess of Vilich and also of St. Maria im Kapitol in Cologne; she was declared a saint post-mortem.

[3] Her parents were Megingoz, count of Guelders, and Gerberga,[4] who was a descendant of German king Henry the Fowler.

As a child, she was given to the convent of St. Ursula in Cologne, probably before 977, where she was educated according to the Rule of St Jerome, and engaged in philosophical studies, according to her Vita.

When her older brother Godfrey died in battle in 977, her parents began funding the construction of a church in his honour at Vilich (today part of Bonn-Beuel) and worked to establish a female monastic community following the rule of the observances of the canonesses.

As part of this process, they redeemed their daughter from St Ursula with a gift of land and established her as abbess of the newly founded community at Vilich.

Initially, Adelaide declined the offer allegedly due to the distance between Vilich and St Mary in the Capitol.

Her favourable reputation increased after bad harvests in the following years, during which Adelaide cared for the people in Cologne.

While her relationship with Archbishop Heribert is described by the vita as one of caritas, the sisters at Vilich are depicted as feeling neglected due to Adelaide spending time in Cologne.

On 5 February of an unknown year, Adelaide died of a sore throat in the company of her friend Archbishop Heribert.

Adelaide was declared Servant of God on 22 November 1922,[13] and canonized by Pope Paul VI on 27 January 1966.