A lost literary work (referred throughout this article just as a lost work) is a document, literary work, or piece of multimedia, produced of which no surviving copies are known to exist, meaning it can be known only through reference, or literary fragments. This term most commonly applies to works from the classical world, although it is increasingly used in relation to modern works. A work may be lost to history through the destruction of an original manuscript and all later copies.
Works—or, commonly, small fragments of works—have survived by being found by archaeologists during investigations, or accidentally by laypersons such as, for example, the finding Nag Hammadi library scrolls. Works also survived when they were reused as bookbinding materials, quoted or included in other works, or as palimpsests, where an original document is imperfectly erased so the substrate on which it was written can be reused. The discovery, in 1822, of Cicero's De re publica was one of the first major recoveries of a lost ancient text from a palimpsest. Another famous example is the discovery of the Archimedes Palimpsest, which was used to make a prayer book almost 300 years after the original work was written. A work may be recovered in a library, as a lost or mislabeled codex, or as a part of another book or codex.