St. Anthony of Padua (Maso di Banco)

You'll need to get up close in order to appreciate this portrait of St. Anthony of Padua, c. 1340, by Maso di Banco, but I think it's worth taking the time.  

Regrettably, not many of di Banco's works have survived.  You can see some of them, however, by consulting his page at Artcyclopedia.