Piero di Cosimo (also known as Piero di Lorenzo) ( 1462- 1521) was an Italianpainter. The son of a Florentinegoldsmith, he apprenticed under Cosimo Rosseli , whom he assisted in the decoration of the Sistine Chapel. He was noted for his rather eccentric personality and unorthodox interpretations of mythological subjects. He also wrote a relatively famous treatise on geometry. Piero's students included Andrea del Sarto.