The patron saint of Senigallia is Saint Paulinus of Nola, celebrated on 4 May. The town preserves the cathedral of San Pietro Apostolo, whose construction began in 1762.
In the first half of the 15th century the town came under the interest of the Riminese Malatesta family, thanks to its strategic position between Pesaro and Ancona: it was Sigismondo Pandolfo Malatesta, in particular, who took such an interest in it that he is considered Senigallia's «refounder». He rebuilt the walls and defensive bastions according to a rectangular plan based on the cardo and decumanus of the Roman town, and gave new impetus to the already existing Fiera della Maddalena, established in the 13th century: he introduced tax breaks for those who moved to the «new town», attracting people from all over Italy, including the founding nucleus of the Jewish community. The fair thus became one of the country's most important duty-free fairs, with goods exchanged from every corner of the Mediterranean, and in the 18th century it even required the town to be expanded to accommodate it.
Senigallia was also the birthplace of Giovanni Maria Mastai Ferretti, who ascended to the papal throne in 1846 as Pius IX: his was the longest pontificate in history after the one traditionally attributed to Saint Peter the Apostle.
