In 1166, a group of Cistercian monks were sent out from Vitsbøl Monastery charged with the task of founding a new monastic settlement in Central Jutland on lands granted to them by the Bishop of Aarhus. The monks ended up wandering for the following six years, temporarily staying in three different locations, until they finally found what was to be their permanent home on a sandy isthmus between Mossø and Gudensø.

The monks named the place Cara Insula, which is Latin for the Precious Island. The name possibly refers to the situation of the monastery on an island formed after the monks had constructed a canal system for their water supply between the two lakes. The name may also allude to the idea that a monastic community was an island in the world, where monks practised an insular lifestyle in relation to the rest of medieval society.

By the middle of the 13th century, the monks had built an abbey and east wing using large burned clay bricks. Apparently, the building project was then put on hold for many years and not resumed until the late Middle Ages, when the monastery again flourished after receiving donations in the form of deeds of gift. During this long interval, the monastery must have consisted not only of the original brick buildings but also of buildings made of lighter materials, i.e. wooden or half-timbered ones.

The fully constructed brick abbey with wings and cross-pattern cloisters surrounding a cloister court as well as administrative buildings outside the abbey close – as can be seen from the remains of the foundations – was not completed until the late Middle Ages, probably only decades before the monastery was closed as a result of the Reformation in 1536.

Despite the closure of the monastery, the monks were permitted to remain at the site, provided they refrained from practising the Catholic faith. Further, they were not allowed to admit any new monks to the monastery. The monastic community consequently died out with the passage of time. After the last monk, Abbot Jens, left the site in 1560, King Frederik II stayed at the monastery for a short period before ordering that “Emsborg Church and Dormitory” as well as other unnecessary buildings be demolished and the bricks, timber and other materials be brought to Skanderborg for use in the construction of the buildings on Skanderborg Castle Hill.