Bibliothecarius

Bibliothecarius is a Latin title meaning keeper or custodian of a library. The term derives from bibliotheca, meaning library (from Greek bibliothekē), with the suffix -arius denoting an office or person associated with something. In medieval and early modern Latin, bibliothecarius referred to the official in charge of a monastery, cathedral, collegiate library, or university library.

Historically, the bibliothecarius supervised the library’s holdings, maintained inventories and catalogues, and coordinated the acquisition of new books through donation, purchase, or manuscript exchange. The role involved arranging manuscripts and printed volumes, overseeing binding and repair, and controlling access and lending. In many institutions the position was filled by a cleric or monk and could be combined with duties as scribe, archivist, or librarian for liturgical books. The office often encompassed responsibilities related to the management of scriptoria, copying activities, and the care of valuable manuscripts and early printed works.

In modern usage, the Latin term is largely historical or ceremonial and is uncommon outside Latin texts or formal ecclesiastical contexts. Contemporary librarians and archivists perform analogous functions, but the title bibliothecarius is typically reserved for historical discussion or for ceremonial use within church or academic institutions. When used, it denotes the person charged with governance and stewardship of a library’s collection, sometimes within a monastic, cathedral, or university setting.