[1] It contains relations of events, legal dispositions, public announcements, edicts, flying sheets and satirical posters.
He had also gathered a large number of legal proceedings and decisions, political speeches, sermons preached regarding diverse events, printed matter of local interest, novels and other brief treatises of different topics.
As of 2018[update], the collection consists of approximately 9,000 volumes and includes the first editions of every Cervantine work in original language and translations; except for La Galatea, which is conserved in the form of a very rare second edition.
The Collection includes the first six editions of Don Quixote (part 1, 1605), bibliophile items and publications of the Cervantine work in more than 50 languages.
In honor of the donor, the Institut d'Estudis Catalans created the Isidre Bonsoms Award to recognize "the best work of investigation, publishing, bibliography, art, critic[ism], biography or music on Cervantes works and on the novels and stories of knighthood and adventures that preceded Don Quixote, as well as on those that it has motivated or influenced".