(anc. Placentia, Fr. Plaisance), a town of Italy, capital of a province of the same name in the duchy of Parma, stands about half a mile from the S. bank of the Po, 2 miles below its confluence with the Trebbia, 37 miles W.N.W. of Parma, and about as far S.E. of Milan. It is of an oblong form, surrounded by ancient walls and ditches, and defended by a citadel which is garrisoned, according to a provision of the Congress of Vienna, with Austrian troops. The streets are in general broad and straight, but dull and deserted; and the grass that grows in many of the thoroughfares shows that the town is much too large for its present population. The most busy part is near the principal square, called Piazza de Carrafi, from the equestrian statues in bronze of Alessandro and Ranuccio Farnese, dukes of Parma. In this square is the ducal palace and the town-house, an edifice built by the merchants of Piacenza in 1281, in a mixed style of architecture, and considered one of the finest buildings of the kind of that century. The cathedral of Piacenza, consecrated in 1132, is a fine building in the ancient Lombard style. In the interior, which is adorned with massive pillars supporting wide-spreading arches, there are many fine paintings by various artists. Of the numerous other churches of Piacenza, many are very fine, both from their architecture and the paintings with which they are adorned. The Farnese palaces, designed by Vignola, was once a most splendid edifice, but it is incomplete; and is now used for barracks. Among the other public buildings are the governor's house, the custom-house, and the court-house. Piacenza contains a college with a library of 30,000 volumes, an episcopal seminary, several schools, two theatres, a hospital, orphan asylums, and many other charitable institutions. It is the see of a bishop, and the seat of a court of appeal and inferior tribunals. The manufactures of the town consist of woollen and cotton cloth, silk, hosiery, hats, and earthenware. Some trade is carried on in cattle and agricultural produce. The ramparts are now partly used as a public walk, and from them may be obtained some fine views—with the Alps and the Apennines in the distance; the city, with its magnificent buildings, in the foreground; and the broad stream of the Po appearing here and there, with its numerous willow-covered islands. The origin of the ancient Placentia is doubtful, being ascribed by some to the Gauls, and by others to the Etruscans. It is of no historical importance before 219 B.C., when it became a Roman colony. It remained faithful to Rome during the second Punic war, which was then raging, and resisted an attack of Hasdrubal. In the year 200 it was taken and plundered by the Gauls, but it soon recovered from this calamity. After the irruptions of the northern barbarians, Placentia was one of the first cities that recovered its prosperity; and it became in the tenth century a place of considerable commerce. It was for some time independent; but after being subject to several lords in succession, it came into the hands of the Visconti of Milan. In 1447 Piacenza revolted from the Milanese, but was retaken in the same year by Francesco Sforza. Under him and his successors it remained until Louis XII. of France took it. It was then retaken by Pope Julius II., and retained by the Papal See, till, along with Parma, of which duchy it has since formed a part, it was transferred to the Farnese family. Pop. 30,500.