a town of Tuscany, Italy, in the province of Siena, 9 m. west of the town of Montepulciano by road, 1611 ft. above sea-level. Pop. (1901), 27 3 0 (town); 3836 (commune). The place was originally called Corsignano and owes its present name to Aeneas Silvius Piccolomini, Pope Pius II. (q.v.) who was born here in 1405. The buildings which he caused to be erected by Bernardo Rossellino in1460-1463form a noble group of early Renaissance architecture round the Piazza del Duomo. The latter retains Gothic details in the interior, but the facade is simple Renaissance work. The ether three sides are occupied by the episcopal and municipal palaces, and the Palazzo Piccolomini; the last, resembling the Palazzo Rucellai at Florence, is the finest, and in front of it is a beautiful fountain. The episcopal palace contains a museum with some fine ecclesiastical vestments, enamels and other works of art.