Rein Abbey

Rein Abbey was a Roman Catholic religious house for women situated on a prominent elevation in Rissa on the Fosen peninsula, northwest of Trondheim in Trøndelag, Norway. Founded in or shortly after 1226 on the ancestral estate of Duke Skule Bårdsson, the abbey was likely established to fulfill a vow following the Duke's recovery from illness. Dedicated to Saint Andrew, the institution served as a community for noblewomen, possibly operating under the Rule of St. Augustine as a collegiate foundation of secular canonesses. Its first abbess was Sigrid Bårdsdatter, the Duke's half-sister, and it later became the final residence for Queen Margret of Norway, daughter of Skule Bårdsson and wife of King Håkon Håkonsson.

The abbey faced significant challenges throughout its history, including a devastating fire caused by lightning in 1317, though the structures were quickly repaired. During the Protestant Reformation, the monastery was dissolved, and its assets were seized by the Crown. In 1531, the influential aristocrat Ingerd Ottesdatter Rømer became its administrator, successfully protecting the remaining community members while acquiring the estate for her descendants. Since 1704, the property has remained associated with the family of Henrik Hornemann, a prominent merchant from Trondheim.

Today, Rein Abbey exists primarily as ruins, with some structural remains visible among later buildings on the site. Although the location has only undergone one archaeological investigation in 1861, the former abbey grounds are officially protected by the Norwegian Directorate for Cultural Heritage. The site stands as a significant historical landmark representing the region's medieval religious life and the powerful influence of the Norwegian aristocracy during the transition from the Catholic era to the Reformation.