Vasari grew up in Tuscany and studied in Florence as a teenager. He also studied in Rome, and worked in Naples and other places. His work as as architect can still be seen in Florence, where passageways he envisioned and built still bear his name, and churches still serve as testament to his talent.
Pope Pius V commissioned his painting titled The Adoration of the Magi (1567) for a church in a small town in northern Italy. The painting was recently restored and displayed in Rome and Naples and will eventually be returned to Santa Croce in Bosco Marengo, the pope's hometown.
But it is as an art historian that Vasari is best remembered. He was the first to create an encyclopedia of artists. He was the first to use the word "renaissance" in print, though others were certainly talking about the phenomenon as it was taking place.
However, Vasari was a bit parochial in his work, titled Lives of the Most Excellent Painters, Sculptors, and Architects (1550). Scholars have noted a decided bias toward artists working in Florence, to the point of ignoring those in Venice and elsewhere. He did include artists working in Rome, perhaps because he had worked in Rome as well. As for artists working in other parts of Europe, forget about. They apparently didn't exist as far as Vasari was concerned.
The book was enlarged and partly rewritten in 1568, and woodcut portraits of the artists were added, including some from Venice after Vasari visited there. Still, the second edition remained largely biased toward Florentine artists.
Nevertheless, scholars and art historians, even today, still consider Vasari's book an important work, and many have used it as a primary source in their own studies of certain artists. In any case, it is hailed as "the most influential single text for the history of Renaissance art." It served as a model for encyclopedias of artists. Furthermore, it gave great insight into the technical aspects of painting, sculpture, and architecture during the Italian Renaissance.
Among the more than 180 artists included in the work are Leonardo da Vinci, Michelangelo, Sandro Botticelli, Taddeo Gaddi, Raphael, Correggio, and Alfonso Lombardi. Giorgio Vasari also included a biography of himself, lest anyone forget him.