On August 29 , 1294 , the hermit Pietro del Morrone was consecrated as pope Celestine V in the church of Santa Maria di Collemaggio , in commemoration of which the new pope decreed the annual religious rite of the Pardon ( Perdonanza Celestiniana ) , still observed today in the city on August 28 and 29 : it is the immediate ancestor of the Jubilee Year .
On August 29 , 1294 , the hermit Pietro del Morrone became pope Celestine V . The ceremony was in the church of Santa Maria di Collemaggio .