For the bust in gilded copper of Pope Mark, dated 1381 and belonging to the abbey of Abbadia San Salvatore, the attribution to the Sienese sculptor and goldworker Mariano d'Agnolo Romanelli has been made, on the basis of stylistic analysis and particularly comparison with the marble sculptures of the Cappella di Piazza del Campo in Siena (1376-1380) and the archaic-style painted wooden bust of 'Saint Ursula' (San Gimignano, Museo Civico). This has revealed that the Sienese artist, who in his marble and wooden figures follows the teachings of the forefathers of the Gothic style Nicola and Giovanni Pisano, reproposes the technique favoured by the great Sienese goldworkers of the early Trecento also in the choice of champlevé enamels following the Tuscan version of this technique (that is, with figures lacking glass paste).