Diocese in the Province of Ancona in the Marches (Central Italy). The city is situated on the Adriatic at the mouth of the Misa, which divides it into two parts. Maritime commerce, the cultivation and manufacture of silk, agriculture, and cattle-raising from the means of support of the population. The fortifications constructed by the dukes of Urbino and by the popes still remain in part. Among the churches besides the cathedral, that of Santa Maria delle Grazie (1491) without the city walls deserves mention; it possesses a Madonna with six saints by Perugino, and another Madonna by Piero della Francesca. The name Senigallia records the Senones, a tribe of Gauls who possessed this city before its conquest by the Romans. The latter founded a colony here called Sena Hadria, but later the name most commonly used was Senogallia or Senigallia. In the Civil War (B.C. 82) it was sacked by Pompey, then one of Sulla's generals. It was pillaged a second time by Alaric, A.D. 408. Under the Byzantine rule it belonged to the so-called Pentapolis. Several times in the sixth and eighth centuries the Lombards attempted to capture it, and, in fact, shortly before the city was bestowed upon the Holy See it was the seat of a Duke Arioldo, who in 772 owed allegiance to King Desiderius. It afterwards shared the vicissitudes of the March of Ancona, and at the end of the twelfth century was the seat of a count. In the wars between the popes and Frederick II it belonged for the most part to the party of the Guelphs, for which reason it sustained many sieges, and was in 1264 sacked by Percivale Doria, captain of King Manfred. Hardly recovered from this calamity, it fell into the power of Guido di Montefeltro (1280). In 1306 it was captured by Pandolfo Malatesta of Pesaro and remained in his family, notwithstanding that they were expelled by Cardinal Bertrando du Poyet and were expelled by Cardinal Albornoz (1355). In 1416 Ludovico Migliorati of Fermo and the cities of Ancona and Camerino formed a league against Galeotto Malatesta, and captured Sinigaglia, but they afterwards restored it. In 1445 it was take by Sigismondo Malatesta of Rimini, who also secured the investiture from Eugenius IV and fortified the city.

After various vicissitudes Sinigaglia was (1474) given in fief to Giovanni della Rovere, a nephew of Sixtus IV. He married the last heiress of the duchy of Urbino, of which the city thus became a part (1508). In December, 1502, Sinigaglia, which had thrown open its gates to Caesar Borgia, was the scene of the celebrated treachery by which Borgia rid himself of his enemies, the petty lords of the Romagna. In 1624 it came under the immediate suzerainty of the popes. In 1683 Turkish pirates disembarked and plundered the city. Sinigaglia was the birthplace of Pius IX and B. Gherardo di Serra (fourteenth century). The patron saint of Sinigaglia is St. Paulinus, whose body is preserved in the cathedral (as is attested for the first time in 1397). He is, therefore, not identical with St. Paulinus of Nola, nor is it known to what epoch he belongs. The first bishop of certain date was Venantius (502). About 562 the bishop was St. Bonifacius, who at the time of the Lombard invasion was martyred by the Arians. Under Bishop Sigismundus (c. 590) the relics of St. Gaudentius, Bishop of Rimini and martyr, were transported to Sinigaglia. Other bishops of the diocese are: Robertus and Theodosius (1057), friends of St. Peter Damianus:; Jacopo (1232-1270), who rebuilt the cathedral which had been destroyed in 1264 by the Saracen troops of King Manfred; Francesco Mellini (1428), an Augustinian, who died at Rome, suffocated by the crowd at a consistory of Egenius IV. Under Bishop Antonio Colombella (1438), an Augustinian, Sigismondo Malatesta, lord of Sinigaglia, angered by his resistance to the destruction of certain houses, caused the cathedral and the episcopal palace to be demolished. The precious materials were transported to Rimini and were used in the construction of S. Francesco ( tempio Malatestiano). Under Bishop Marco Vigerio Della Rovere (1513) the new cathedral was begun in 1540; it was consecrated in 1595 by Pietro Ridolfi (1591), a learned writer. Other bishops were Cardinal Antonio Barberini, a Capuchin brother of Urban VIII; Cardinal Domenico Poracciani (1714); Annibale della Genga (1816), who afterwards became Pope Leo XII. The diocese is suffragan of Urbino; it has 48 parishes with 114 secular and 78 regular clergy; 92,000 souls; 15 monasteries for men; 19 convents for women; and 3 institutes for female education.

U. BENIGNI