This book offers a new edition of one of the most important art historical sources on Italian art. Written not long before Vasari's famous Lives (1550), this source provides an overview of art from Cimabue to Michelangelo. Moreover, the author's ambition was to provide a sketch of the art of classical antiquity. First published in the late nineteenth century, the Codex has led to numerous questions, the main one being: who was its author? We believe we have found the answer to this question, which led us to come up with a new edition of the Codex.