Pietro Paolo Drei (Petro Pauolo Dreio or Pietro Paulo Dreo) (c.1600 – 1656) worked for the Fabbrica of St Peter's Basilica, first as a fattore (under supervisor) and later as a soprastante (foreman and architect's assistant).[1] He was the son of Benedetto[2] (c.1580 – 1637), also a fattore of the Fabbrica, whom he assisted with flower mosaics on the floor of St Peter's Basilica for 13 years – from approximately 1620.[3] This involved creating imagery by arranging vibrant flower petals. In the works, whole flowers, individual petals, and petals which had been cut into smaller pieces made up the composition.[4]