FRONTONE. – The upper terminal part of a façade, generally triangular in form so as to follow the slope of the roof.
It was adopted in the earliest Christian buildings (Constantinian basilicas, Syrian churches); but in Romanesque and Gothic churches, although the façade almost always ends in sloping lines, it rarely takes the form of a f., because there is no cornice separating it from the part below. The classical arrangement returned during the Renaissance. In the second half of the fifteenth century, the curvilinear form remained confined to Venice and the area under Venetian influence (S. Maria dei Miracoli, S. Zaccaria). In the seventeenth century, the f. too took on that sense of movement and tension which characterizes all the architecture of the period; broken forms appeared (S. Maria in Campitelli in Rome), as well as mixtilinear ones, in which Borromini stands out above all. The Neoclassical age brought this element back to the simplicity of its original lines, but with a sense of coldness and rigidity.
In a broader sense, the name f. is also given to the crowning element of windows, portals, and altars. In windows it already appeared sporadically in the Early Christian period (S. Salvatore di Spoleto) and in the Romanesque period (the Baptistery of Florence). The first example of a curvilinear f. in windows is that of S. Salvatore al Monte by Cronaca; the motif was adopted by Michelangiolo (the sacristy of S. Lorenzo) and rapidly disseminated, also alternating with the triangular form on the same façade. The bizarre invention of inverted frames is found in Buontalenti (the Porta delle Suppliche in the portico of the Uffizi in Florence, 1580) and was entirely episodic; but already in this period there began the very frequent seventeenth-century use of the interrupted f., leaving space at the center for decorations or coats of arms.