On September 1, 1486 the Venetian Senate granted a privilege to the humanist Marco Antonio Sabellico (Marcus Antonius Sabellicus) for the printing of his Decades rerum Venetarum, a history of Venice.
This document, preserved in the Venetian State Archives (ASV, NC, reg. 11, c.55r) was the first recorded privilege granted to an author, recognizing the right of Sabellico to authorize the publication of his work, and to secure protection against unauthorized printings or pirated editions. This document has been called the first known author's copyright.
"Sabellico's privilege set the precedent for the custom of granting privileges not just to the printers but also directly to the authors. Such privileges are best understood as an extension of the traditional patronage system and as a form of reward rather than ownership. Sabellico's privilege was an exceptional arrangement in the sense that it was a form of reward for a literary work which promoted the public interest, rather than an assertion of the inherent rights of the author" (Primary Sources on Copyright (1450-1900), eds L. Bently & M. Kretschmer, www.copyrighthistory.org, which also reproduces an image of the document, an English translation, and commentary).
Sabellico's Decades rerum Venetarum was first published in print in Venice on May 21, 1487 by Andreas Torresanus, de Asula. ISTC no. is00005000. In November 2013 a digital facsimile was available from the Bayerische Staatsbibliothek at this link.