In March 1416, the will of William Loring was proved, which bequeathed three volumes to the library thus: "Item volo quod omnes libri mei juris civilis remaneant in communi libraria scolarium universitatis Cantebrigg' in perpetuum."

[7] From the 16th century, the library received generous donations or bequests of books and growth was considerably increased once the privilege of legal deposit had been granted.

The site selected comprised the 8 acres (3.2 ha) joint cricket field of King's and Clare Colleges.

[11] Inside are a number of 17th and 18th century bookcases including those designed for the old University Library by James Essex in 1731–34.

Sensing that it needed a grander entrance, Rockefeller persuaded the architect to add the distinctive front-facing tower.

The building bears a resemblance to Scott's industrial architecture, including Bankside Power Station (now Tate Modern).

[14] The library has been extended several times through ground annexes and underground extensions which allowed for new legal deposit documents to be stored.

The University Library has also built a large storage facility in Ely which has more than 100 kilometres of shelving for future legal deposit books and periodicals.

Work on a £17.1 million off-site facility to house the growing collection finished in 2018 and provides Cambridge University with one of the largest library storage buildings in the world.

Significant digitisation efforts continue as more manuscripts and early-modern books are acquired and scanned by the University of Cambridge.

In 2002, the library began a special project termed Janus (after the Roman god) to provide a single point of networked access to catalogues of archives and manuscript collections held throughout Cambridge.

A widening number of participating repositories, both University and non-University, are working together to provide comprehensive coverage of archives in the city and surrounding area.

Members of the Friends regularly raise funds for future construction projects and archival restoration efforts, as well as the acquisition and purchase of rare books or manuscripts.

The Friends of the Cambridge University Library has raised more than £150,000 through regular and special donations over the past five years.

[24] In 1721 the post of Principal Librarian (Protobibliothecarius) was created for Conyers Middleton "as a mark of sympathy with him in his opposition to Richard Bentley".

Abraham Wheelocke was librarian of the "Public Library" at Cambridge University, and was also Reader in Anglo-Saxon in the 17th century.

More recent University Librarians have included Eric Bertrand Ceadel, F. W. Ratcliffe (1980–94), Peter Fox (1994–2009) and Anne Jarvis (2009–16).

Other notable members of staff include the bibliographer Henry Bradshaw and the Uranian poet Charles Edward Sayle, author of a history of the library.

The exhibitions are sponsored by the Cambridge University Library and are organised by the team of librarians and leading academics in the field.