Look for Ghiberti 's vigorous bronze of the city 's patron St. John ( east wall , on the Via de ' Caleiuoli ) ; St. Matthew , the bankers ' tax-collector turned Apostle ( west ) ; Donatello 's St. George , the armorers ' dragon-killer ( north , a bronze cast of a marble original in the Bargello ) ; St. Mark , whose vividly sculpted robes do credit to the linen-drapers he protects ( south ) ; and Nanni di Banco 's outstanding conspiratorial group of Four Crowned Martyrs for the sculptors ' own guild of stonemasons and wood-workers ( north ) .
Ghiberti was a sculptor .