This sculpture group shows a set of Romanesque-figured men in togas somberly facing each other inside a semicircular niche, and was commissioned by a guild of stone and woodworkers in homage to a group of artists executed for refusing to build a statue of Asclepius for Diocletian.  
This piece is framed at the top by a semicircular arch under a central gable with a relief of the torso of a robed man touching his hands to his chest.  The marble relief below this sculpture group shows the construction of a spiral column on the left and a nude cherub on the right in a workshop scene depicting its main subjects in action.  This sculpture group shows a set of Romanesque-figured men in togas somberly facing each other inside a semicircular niche, and was commissioned by a guild of stone and woodworkers in homage to a group of artists executed for refusing to build a statue of Asclepius for Diocletian.  Located along with works by Ghiberti and Donatello in Florence's Or San Michele, this is, FTP, what sculpture group depicting a quartet of doomed Christian sculptors, the masterpiece of Nanni di Banco?
This piece is framed at the top by a semicircular arch under a central gable with a relief of the torso of a robed man touching his hands to his chest.  
Four Crowned Martyrs or Four Crowned Saints or Quattro Santi Coronati