John, Constable of Portugal — Portrait believed to be of Infante John, Lord of Reguengos de Monsaraz, Constable of Portugal. Detail from the fifth panel of the polyptych Adoration of Saint Vincent, attributed to Portuguese Renaissance painter Nuno Gonçalves, composed c.1470 (possibly as early as 1450s). Originally found at the monastery of São Vicente de Fora, now held by the National Museum of Ancient Art in Lisbon, Portugal.
Photo Credit: By Nuno Gonçalves - Panels of St. Vincent, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12632887