Sightseeing in Tuscany picture - Commencement of works on 9 August of the year 1173. 1182 Establishment of the "Opera Campanilis petrarum Sancte Marie" (Stone Works of the bell tower of Saint Mary). 1185 Probable interruption at the height of the 4th order 1198 The presence of a bell-ringer at the Tower is documented - a sign that the building can hold at least one bell, partially fulfilling the purpose for which it was intended 1231 Building work, probably taken up again in the first decades of the century, proceeds. A workshop in which marble for the Tower is worked is documented 1233 Oath of the worker Benato Bottici: in the ceremony of investiture he pledges to be "solicitous and attentive in the building of the bell tower of the church, according to the means of the Opera".