Italian astronomer, cartographer and engineer, active beginning 1539 in Venice, Gastaldi is considered the foremost Italian cartographer of the 16th century along with Paolo Forlani. By the 1540’s, as cosmographer to the Republic of Venice, he had developed a distinctive style of copper engraving that led to his maps being used as a source by many mapmakers, including Camocio, Bertelli, Forlani, Ramusio, Cock, Luchini and Ortelius. He engraved 60 copperplate maps for Pietro Andrea Mattioli’s Italian edition of Ptolemy‘s “Geographica” entitled “La Geographica di Claudio Ptolomeo Alessandrino…”