The Coptic Collection
Textually the collection of Coptic manuscripts (on parchment) is interlinked with the Coptic papyri collection, as similar texts were in circulation written on both media; the choice of material being dependant on the resources of the community. The books are written in the Coptic language which has four principal dialects, Bohairic, Fayumic, Sahidic, and Akhmimic, most of which are reflected in various ways in the Chester Beatty manuscripts, either as the main text or as later glosses.
The most important manuscripts were acquired by Chester Beatty from dealers in Cairo in the 1920s. One purchase included three of five books that came from the Monastery of Apa Jeremias at Saqqara (the remaining two belong to the University of Michigan). These manuscripts (Cpt 813, 814, 815) were written in the Sahidic dialect and date from c. A.D. 600. They were found with some coins (Alexandrian 12-nummia pieces) and fragments of bone belonging to the bindings. The bindings of these manuscripts are among the earliest examples of Western binding structures with decorated leather tooling and ornamented drawings on the edges of the parchment.
Thompson, Herbert (1932) The Coptic Version of the Acts of the Apostles and The Pauline Epistles in the Sahidic Dialect, London:
Quecke, Hans (1984) Das Johannesevangelium Saidisch, Papyrologica castroctaviana, Vol. 11.