The Dombibliohek owns a collection of about 1000 early modern manuscripts. Among them are chronicles and diaries of the 16th and 17th century.
One of them is the Brandis diary, written by a dynasty of Hildesheim mayors who tell us about life from 1454 – 1661 (HS 73 – HS 78, HS 80).
Conrad Jordan, a doctor and archivist, kept a diary during the Thirty Years' War, chronicling the years 1625 – 1659 (HS 179a/b).
A valuable source for the time of the Protestant Reformation in Hildesheim are the annals of cleric Johannes Oldecop. The oldest preserved copy is from 1609 (HS 81).
In addition to these prominent works, the collection feautures a plethora of diverse material like cartularies, texts about the history of monasteries and religious law, certificates of religious vows, lists of taxes and houses, or a collection of inscriptions.