the manuscript as it exists today consists of two vellum codices which were originally separate works but were bound together sometime before 1648. this was done at the request of their new owner, irish antiquarian sir james ware (d. 1666), who thanks to dubhaltach mac fhirbhisigh (d. 1671) had been able to assemble a fine collection of irish manuscripts. several leaves of paper with a (mainly) latin commentary by ware on aspects of irish history (fos. 13–18) were inserted between the two manuscripts, possibly to preserve the appearance of two distinct works. further paper folios were added at the end of the second manuscript (fos. 90–103), containing notes and transcripts of documents, part of which was written in latin.