Inaugurated in 1953, the Istituzione Biblioteca Città di Arezzo was created by merging several different libraries and by establishing a consortium whose members include the Commune, the Province, the Fraternita dei Laici [Brotherhood of Laymen] and the Accademia Petrarca di Lettere Arti e Scienze. Especially interesting among the libraries forming part of the institution is that of the Laymen’s Brotherhood, an association founded in 1262 and constituted at a later time as a charity organisation. Open to the public already in 1634, the library of the Brotherhood contains, along with numerous records coming from suppressed religious congregations, the library of Francesco Redi, the most important part of the City Library as well as the Passerini Library of Dante's works, owned by the Petrarch Academy. Some manuscripts coming from the Library of the Camaldoli Monastery are also kept here.