The extent of Claudius Galen's written work was so great that Galen himself felt the need to provide a bibliography organizing and explaining his own writings. He also felt the need to distinguish between works that he had actually written and works that were being falsely attributed to him. About 190 CE Galen wrote two classified bibliographies of his own writings: Peri ton idion biblion [Latin: De Libris propriis liber, On his own writings] and Peri tes taxeos ton idion biblion [Latin: De ordine librorum suorum liber, On the arrangement of his own writings]. These are the first auto-bibliographical works which survived, and they may also be considered the first bibliographies of any kind which survived after the listings from the library of Alexandria by Kallimachos (Callimachus), which survived only in the most fragmentary form.
"The De libris propriis liber opens with a general introduction, in which Galen refers to the books falsely attributed to him. The main text is divided into seventeen chapters, in which Galen arranges his works under such headings as commentaries, anatomical works, Hippocratic writings, works on moral philosophy, grammar and rhetoric, and so on. This bibliography apparently did not suffice as a guide to the five hundred or so works Galen had put out (many of them now lost), for he added a second one. This is the De ordine librorum suorum liber, of which second bibliography unfortunately only a fragment has come down to us" (Besterman, The Beginnings of Systematic Bibliography 2nd ed (1940) 3, nos. I & II).
Galen's bibliographies were first published in print in Part IV, ff.**1-6, of the editio princeps of his collected writings in Greek issued by the heirs of Aldus Manutius and Aldus's father-in-law, Andreas Asulanus, in Venice in 1525. They were revised and improved by Conrad Gessner for an edition published in Basel in 1562.