The site of the cathedral, as in other cities of ancient origin is located at the limits of the Roman city: the central spaces of the Roman Lucca were heavily urbanized and the project was not yet feasible, which is to be for the Church of Saint Michael to use the orifice space. The Romanesque church had to have a basilica body with five aisles, supported by columns surmounted by women’s gallery, wooden rooftops. The porch built subsequently still retains a series of shelves on which a plank had to be stretched in order to form a passage that joined the women’s gallery. The main façade oriented to the West leans against the portico-narthex open on the square by three large arches, one of which is closer to the proximity of the pre-existing bell tower. Guidetto and his collaborators in opera bas-reliefs with the martyrdom of Saint Regulus depicted in the lunette placed above the entrance of the right aisle, a cycle of the months and stories of Saint Martin; In the lunette and lintel of the entrance to the left aisle was finally placed the extraordinary deposition of Nicola Pisano, one of the most advanced works of the time (about 1260).