As the first Italian art historian, Vasari initiated the genre of an encyclopedia of artistic biographies that continues today. Vasari's work was first published in 1550 by Lorenzo Torrentino in Florence, and dedicated to Grand Duke Cosimo I de' Medici. It included a valuable treatise on the technical methods employed in the arts. It was partly rewritten and enlarged in 1568 and provided with woodcut portraits of artists (some conjectural).
The work has a consistent and notorious favour of Florentines and tends to attribute to them all the new developments in Renaissance art—for example, the invention of engraving. Venetian art in particular, let alone other parts of Europe, is systematically ignored. Between his first and second editions, Vasari visited Venice and the second edition gave more attention to Venetian art (finally including Titian) without achieving a neutral point of view. John Symonds claimed in 1899 that "It is clear that Vasari often wrote with carelessness, confusing dates and places, and taking no pains to verify the truth of his assertions.", while acknowledging that despite these shortcomings, it is one of the basic sources for information on the Renaissance in Italy.