It was the scientific diligence of abbots like Herrand, Martin and Sigebodo, which made it possible, with the help of numerous wealthy sponsors, for Ilsenburg Abbey, founded in the early 11th century, to acquire an extensive library or to produce books in their own scriptorium. Monasteries were places not just of worship but also of intellect, knowledge, culture and book production.
Concerning the remains of the library, we have, according to Eduard Jacobs, a catalogue (Catalogus Librorum) of 244 items, of which 156 are manuscripts and 87 printed works, only one item could not be categorised. The catalogue had been compiled in 1574 on the instruction of the abbey administrator, Count Christoph of Stolberg-Wernigerode. It contained Bible texts, writings of the church fathers and exegetical, ascetical, and liturgical writings, particularly sermons.
Especially important are a further 13 documents on the law for use by the abbey administration. A contemporary, the reformer Winnigstädt (died 1569) knew the original size of the Ilsenburg library and certified to Abbot Herrand, whom he also counted among the foremost ecclesiastical writers, that “he had established a good school for all kinds of free arts and a magnificent library …at great expense”. The library remained until the Peasant War (1525) and was then pillaged and destroyed. The subsequent history of books and records reads like an adventure.