The primitive church was built inside the Castle of Casole, a village that drew its wealth from the fact of being located along one of the tracks of the via Maremmana and from being since the XI century one of the cornerstones of the bishop of Volterra for the control of the territory. The ecclesia s.Marie in Castle quod dicitur Chasuble is named for the first time in an act of Guido, bishop of Volterra between 1039 and 1046. From the outset therefore enjoyed considerable prestige so that before 11 October 1152, Date oldest remained, was already equipped with a cloister where were drawn up the most important public acts of the life of the castello di Casole. For all the three hundred the pieve casolana maintained its role in the church volterrana becoming also the seat of the diocesan caposesto for the Valdelsa and could count on annuities substantial. In the second half of the century inside the church the side chapels were decorated by local lords and also by some lay companies that had formed, such as for example the Company of Santa Croce which was made the subject of a donation on 15 June 1348. Originally a church was a basilica apsidal area covered with a roof but currently presents itself as a church to hut with transept, choir and side chapels. At the center are of semicolumns ending with capitals of style volterrano and between columns opens the linteled portal surmounted by a lunette monolithic and ring decorated with vegetable motifs and geometrical patterns that are very similar to those of the parish of Saint Paul at Coiano or to the parish of Black. The bell tower has a structure and mighty few openings: at the first level a narrow slit, according to a single lancet window centinata double sguancio, buffered today and to the upper level four large windows at the height of the bell cell. The interior, however, was originally divided into three naves with six spans resting on columns and pillars polilobati. At the end of each of three naves there were as many apses, of which only the central one protruded outside while the two minors were incorporated into the thick dry masonry of the forum as in the pieve of Mensano or in that of Conèo. Under the presbytery was the crypt the surface of which corresponded to the last spans of the basilica; such crypt was removed at the end of the XIII century and rebuilt with the same measurements and Spatial division in the church of San Niccolò. Currently the church has only one nave with ceiling truss discoveries and with the transept fourteenth-century that was connected to the old church with a large arch acute sixth and in its end wall was opened a chapel of the choir, flanked by two smaller by each party.
