Willem Drost studied with Rembrandt around 1650. He probably completed this painting in Venice, where he died at age twenty-six. The chalice identifies the figure as John the Evangelist, Christ’s beloved disciple, who survived an attempted poisoning. Images of early Christian leaders were popular with both Catholic and Protestant buyers, but no one knew what these historical figures looked like. In giving Saint John his own features, Drost may be expressing personal devotion, or may simply have turned to the most convenient model.