Its birth is linked to Canon Don Virgilio Orsini, a man of letters and historian who, in the 1960s, worked hard for its establishment by purchasing many of the volumes that are still preserved here, even at his own expense. Over time, donations from organisations and private individuals were added to the original fund he had set up, thus making the library holdings ever more substantial.

Initially located in the bishop’s palace, after a period of closure lasting several years, the library reopened in December 2002 in its new home inside the Diocesan Cultural Centre of Santa Chiara, which was set up in some rooms of the former monastery. The reading room is located in the former parlor of the Poor Clares.

The book heritage consists of more than eighteen thousand publications, whose largest and most important portion is dedicated to Abruzzo and the history of the Kingdom of Naples. This was the result of a specific will of the founder, who, in order not to disperse forces and means, decided to focus his attention on a single sector, namely the one concerning the history of the country. It also houses books and documents that belonged to the Sulmonese jurist and philosopher Giuseppe Capograssi: some valuable volumes and a rich newspaper library.