"Italian medallist and gem-engraver. Beginning his career in Milan, he moved to Venice in the early 1540s and to Rome in 1546, to work for the ...
papal mint. On stylistic grounds a medal of Pope Julius III (1550-55) is attributed to de Rossi, but his first signed medal is of Pope Marcellus II (1555). From 1557 to 1560 de Rossi resided in Florence, and in 1557 he accepted a commission to carve a large cameo showing Cosimo I de’ Medici, Grand Duke of Tuscany, and his Family (Florence, Palazzo Pitti), from a preliminary drawing (Oxford, Christ Church) attributed to Vasari; the cameo admirably displays de Rossi’s technical brilliance.
In 1560 he returned to Rome, and in 1561 he became warden of the papal mint, a position he retained until his death. In this post he produced not only papal medals but a medal of St Carlo Borromeo, Archbishop of Milan." - http://www.wga.hu/bio_m/r/rossi_g/biograph.html
