Beginning at the corner of the northern side, facing towards the Duomo, we have the minor Art of the Butchers represented by Donatello's St. Peter in marble, an early and not very excellent work of the master, about 1412 (in a tabernacle of the previous century); the _tondo_ above containing their arms, a black goat on a gold field, is modern. Next comes the marble St. Philip, the patron saint of the minor Art of the Shoemakers, by Nanni di Banco, of 1408, a beautiful and characteristic work of this too often neglected sculptor. Then, also by Nanni di Banco, the _Quattro incoronati_, the "four crowned martyrs," who, being carvers by profession, were put to death under Diocletian for refusing to make idols, and are the patrons of the masters in stone and wood, a minor Art which included sculptors, architects, bricklayers, carpenters, and masons; the bas-relief under the shrine, also by Nanni, is a priceless masterpiece of realistic Florentine democratic art, and shows us the mediæval craftsmen at their work, the every-day life of the men who made Florence the dream of beauty which she became; above it are the arms of the Guild, in an ornate and beautiful medallion, by Luca della Robbia. The following shrine, that of the Art of makers of swords and armour, had originally Donatello's famous St. George in marble, of 1415, which is now in the Bargello; the present bronze (inappropriate for a minor Art, according to the precedent of the others) is a modern copy; the bas-relief below, of St. George slaying the dragon, is still Donato's. On the western wall, opposite the old tower of the Guild of Wool, comes first a bronze St. Matthew, made together with its tabernacle by Ghiberti and Michelozzo for the greater Guild of Money-changers and Bankers (Arte del Cambio), and finished in 1422. The Annunciation above is by Niccolò of Arezzo, at the close of the Trecento. The very beautiful bronze statue of St. Stephen, by Ghiberti, represents the great Guild of Wool, Arte della Lana; originally they had a marble St. Stephen, but, seeing what excellent statues had been made for the Cambio and the Calimala Guilds, they declared that since the Arte della Lana claimed to be always mistress of the other Arts, she must excel in this also; so sent their St. Stephen away to the Cathedral, and assigned the new work to Ghiberti (1425). Then comes the marble St. Eligius, by Nanni di Banco (1415), for the minor Art of the Maniscalchi, which included farriers, iron-smiths, knife-makers, and the like; the bas-relief below, also by Nanni, represents the Saint (San Lò he is more familiarly called, or St. Eloy in French) engaged in shoeing a demoniacal horse.