Pisa, city in central Italy, capital of Pisa Province, in Tuscany (Toscana) Region, on the Arno River, near the Ligurian Sea. The city is a rail and road junction and a tourist and industrial center. Important manufactures include textiles, machinery, processed foods, pharmaceuticals, and glass. Among the educational institutions are the University of Pisa (1343), a teachers college, an engineering school, a veterinary institute, and an agricultural school.The principal landmarks of Pisa are grouped in the area of the Piazza del Duomo (Cathedral Square) and include the cathedral, the baptistery, and the bell tower (campanile). The cathedral, a great white marble edifice in the Romanesque style, was begun in 1063. The richly decorated facade was added in the 12th century. The baptistery, begun in 1153, is a circular building in the Romanesque style crowned with a great dome and lavishly ornamented in the 14th century in the Gothic style. The bell tower is known as the Leaning Tower of Pisa, and is a popular tourist attraction. Construction began in 1174 but was suspended when the builders became aware that the shallow foundation would be inadequate in the soft soil. The structure was nevertheless completed by the second half of the 14th century. The Leaning Tower is cylindrical in shape, with eight arcaded stories, and leans about 10° (about 16 feet) from the vertical. The tower had to be closed to visitors beginning in 1990 because of concerns that it was structurally unstable. Work to make the tower's foundation more secure was undertaken in 1992.
An Etruscan town, Pisa became a Roman colony in the 2nd century bc. In the 9th century ad the city was a naval power. Pisa and its ally Genoa drove the Saracens from the islands of Sardinia and Corsica in the 11th century. Thereafter commercial rivalry between Pisa and Genoa led repeatedly to war. In the 12th and early 13th centuries Pisa attained its greatest power in commerce. During the political struggles that occurred in Italy during the Renaissance, Pisa belonged to the Ghibelline faction, which supported the Holy Roman emperors against the papacy. The opposing Guelphs were led by Florence, which wanted control of Pisan trade. Pisa was weakened in 1284, when the Genoese defeated its navy. In the next century Pisa won some victories on land, but in general its military situation worsened. In 1406 the city fell to Florence. Pisa regained its liberty in 1494 but in 1509 fell again to Florence. For later history, see Florence. Among the notable citizens of Pisa were Galileo and the sculptors Nicola and Giovanni Pisano and Andrea Pisano.
