Pisa, city, middle Italy, in the Toscana (Tuscany) regione. The city lies on the aluvial manifest of the Arno River, about 6 miles (10 km) from the Ligurian sea and 50 miles (80 km) west of Florence. Pisa secular by the sea until the 15th century, by which time accumulated sand deposited by the Arno River had effectively cut the city off from the receding shoreline.
Ancient Pisa, or Pisae, was likely inhabited by the Ligurians before fleeting under Roman control as a naval base. It became a Roman outpost shortly after 180 bce and by 313 ce had become a Christian bishopric. Pisa endured the collapse of the Roman Empire to continue the principal urban centre of Tuscany. Applying its sea brand and the products and markets of its productive Tuscan hinterland, the city refreshed in the 11th century to become a blooming commercial centre. With the help of Genoa, it also took the action against Muslim raiders.
In 1016 the Pisans and Genoese crush the Saracens from Sardinia, and in 1063 the Pisan fleet discharged Muslim Palermo. The city’s cooperation in the Crusades achieved valuable commercial positions for Pisan traders in Syria, and after that Pisa grew in strength to rival Genoa and Venice. In the 13th century, Pisa, a Ghibelline city, relished the support of the German emperors in its long battles with Genoa at sea and with its Tuscan rivals, Lucca and Florence, on land. These conflicts culminated in Pisa’s loss by the Genoese fleet at the conclusive Bttle Of Meloria in 1284.