Giorgio Vasari, an artist and biographer of the Italian Renaissance, states that Pisanello also worked in the workshop of Andrea del Castagno, author of the painted equestrian monument of Niccolò da Tolentino (1456) in the Cathedral in Florence. He must also have known Paolo Uccello, the painter of the Battle of San Romano with its many horses. Pisanello's love of drawing horses probably finds its origin in this relationship; but as there is so much unknown of his life, this attribution by Vasari is not reliable and may only be a legend.