Study of an apostle's head and architectural study, Leonardo da Vinci, between 1494 and 1498

Date: between 1494 and 1498. Dimensions: height: 252 mm (9.92 in); width: 172 mm (6.77 in). Medium: pen and ink on paper, red chalk. Collection: Royal Library at Windsor Castle. Leonardo da vinci, Study of an apostle's head and architectural study