This piazza has always represented the heart of the city. In fact the Romans first settled here when, to better fight off the Ligurian peoples, they extended the Cassia road beyond the Fiorentine territory.
The Pistoia of Roman times was confined to the area that would later be enclosed in the first city wall; today traces can still be seen in the many artifacts that have been brought to light during archaeological excavations.
In the layout of the Roman city, what today is the piazza was really the crossroads between the two main streets: the cardo maximus and the decumanus maximus which traditionally determmined the regularity of the urban plan.
The Cassia road, corresponding to the decumano, came from the side of the square where the Palazzo degli Anziani, would be built in later Medieval times and continued along what is now via degli Orafi.
The cardo maximus can be seen today in via Bracciolini. At the intersection of the two, there was the forum and an aristocratic residence whose existence is proved by an elegant mosaic floor. Presumably the piazza had witnessed a more ancient Etruscan settlement, as is suggested by the two stone funerary markers found nearby and now displayed in the archaeological section of the Palazzo dei Vescovi.
After the barbarian invasions and the rise to power of the Lombard governor, the piazza lost its central function in public life and the focus of activity shifted temporarily to the area around the piazza della Sala where the governor's house had been built.
The cathedral square regained importance in Medieval times: it was the marketplace, a use it still conserves today, and it became once more the political and religious center of Pistoia. In that period it developed the characteristic appearance it has today: a large open space defined by excellent examples of Romanesque and Gothic architecture that make it one of the most beautiful squares in Italy.
The Cathedral of San Zeno and the Baptistery of San Giovanni in Corte were built in the eleventh century later the Palazzo dei Vescovi and the first nucleus of Palazzo Pretorio were constructed. Around the end of the thirteenth century a whole quarter was demolished to make way for the Palazzo del Comune.
In the 1600s the cathedral's new tribune was built. A hundred years later the fourteenth-century Loggia degli Anziani (which several prints of that period show near the bell tower) was torn down; in the same period Baron Bracciolini built the palazzo that today houses a bank.
In the nineteenth century Palazzo Pretorio, the old prefectural building, was enlarged; today the prefecture is located in a building constructed in the first half of this century, replacing an older construction that the Pistoians used to call the palazzaccio for its unfinished look.
Today the piazza del Duomo continues to concentrate around it, in a unique way, all the most important buildings of religious, political and judicial power.
Every year on July 25, the city districts compete in a real palio organized in the piazza del Duomo. Although it is simply a continuation of the more ancient corsa dei Berberi, the Giostra dell'Orso (or Joust of the Bear) recreates the games that were in use in the Medieval city. The competing horsemen have to strike the target shaped like a bear - the animal found on Pistoia's coat of arms with their lances. Each rider represents one of the city quarters which are referred to with the names of their symbols: the Dragon, the White Deer, the Grifon, the Gold Lion. It is a spectacular and fascinating tournament that marks the end of the festival of July when the city hosts many cultural events.