Source Material for the Abbey
The fact that relatively many of the convents were founded by noble families was characteristic for Sweden. Askeby is one example. Property was often donated to the abbeys, although it was generally under the control of the families. During the 13th century, gifts were received from other categories of inhabitants.
The archives at Askeby abbey were destroyed in the well-known, big fire in 1377, but the transactions are preserved in other archives. The most important one includes the card-indexes of Swedish Diplomas with medieval letters consisting of 246 documents, starting from 1258. These letters tell us, for instance, how the ownership of the abbey eventually became centralized to the areas east of Stångån, a part of Östergötland known as Östanstång.
There is only one preserved letter from Askeby abbey. When the abbey closed, everything was meant to be destroyed.
But when searching numerous archives, the National Archives of Sweden, the Diocesan Archives, etc., and after studies of abundant international and Swedish research literature, we get a relatively comprehensive picture of the abbey.
Concerning preserved manuscripts, Vreta abbey is better off having about 30 letters preserved, and Nydala abbey having more than 400 letters.