After the death of Emperor Frederick II, Sicily passed to the Angevins, then followed by the Spaniards of Aragon. The Aragon period (1282-1409) is characterized by a political, economic and demographic decline of Mazara. The city passed under the control of the Savoy crown in 1713, a reign which lasted only five years, being replaced by the Austrians (for 16 years) followed by the Bourbons. In 1860 the city was finally conquered by Giuseppe Garibaldi and the Mille, thus joining the Kingdom of Sardinia.
The city was known as Mazzara del Vallo until the World War II period, following which the spelling was changed to Mazara del Vallo.
Mazara del Vallo is among the Italian cities with the highest percentages of immigrants; it is estimated that the city hosts at least 3,500 registered immigrants, mainly from nearby Tunisia but also the other countries of the Maghreb. They tend to live principally around the old Arab city centre (the Casbah). There exists a local school, managed by the Tunisian government, at which only Arabic and French are taught as languages. This has led to some controversy. It must be noted that most of the local schools show openness to Arab culture, even providing Arabic language classes for both Italians and Arabs, and encouraging integration with the autochthonous students. The local city council also provides a seat reserved for a representative of Mazara's immigrant community.
Mazara made national news in March 1998, when a bronze statue called the Dancing Satyr (Satiro Danzante) was found off the port, at a depth of 500 meters in the Strait of Sicily by a local fishing boat. The statue is believed to have been sculpted by Greek artist Praxiteles and is now on display to the public in a dedicated museum in the city, after having been on show at the Chamber of Deputies of Rome, and in Aichi, Japan. After this event, the city quickly gained in terms of visiting tourists and a national advertising campaign was mounted with the slogan Mazara del Satiro.
Other attractions include the Norman Arc, that is the remains of the old Norman Castle built in 1073 and demolished in 1880, and a number of churches, including the Royal Saint Nicholas (San Nicolò Regale) Church, a rare example of Norman architecture built in 1124, the Seminary, built in 1710, which surrounds the main local piazza, Piazza della Repubblica, and St. Vitus on the Sea (San Vito a Mare) Church. In honour of St. Vitus, the official patronal saint as well as a native of Mazara del Vallo, the St. Vitus Feast (Lu Fistinu di Santu Vitu) is held every year.