 The edifice was damaged by the large earthquake of 26 November 1545, and the apse began to subside, a problem which persists to the present day.In April 1473, Bishop Tommaso della Testa Piccolomini presided over the first diocesan synod held in Pienza.On 23 May 1594, Pope Clement VIII separated the two dioceses of Pienza and Montalcino.