 When attributed as a van der Weyden in the early 20th century, there was much speculation amongst art historians as to the sitter's identity.He was identified as a member of the d'Este family from the crest on the reverse, and long thought to be Francesco's father Lionello, an Italian and highly placed Burgundian prince and patron of Rogier.In 1939 Ernst Kantorowicz identified the man as Lionello's illegitimate son Francesco (c. 1430 – after 1475), which is now generally accepted.