Ancient age
Archaeological findings have proved that Prato's surrounding hills were inhabited since Paleolithic times. The plain was later colonized by the Etruscans. In 1998 remains of a previously unknown city from that civilization were discovered in the neighbourhood, at Gonfienti (Prato) near Campi Bisenzio: it was of medium size and it was already a centre for wool and textile industry. According to some scholars, it could be the mythical Camars. The Etruscan city was inhabited until the 5th century BC, when, for undisclosed reasons, it decayed; control of the area was later shifted to the Romans, who had their Via Cassia pass from here, but did not build any settlement.
Middle Ages
In the early Middle Ages the Byzantine and Lombard dominations followed. The history of Prato itself begins from the 10th century, when two distinct villages, Borgo al Cornio and Castrum Prati (Prato's Castle), are known. In the following century the two settlements were united under the lords of the castle, the Alberti family, who received the imperial title of Counts of Prato. In the same period the plain was dried and a hydraulic system regulating and exploiting the waters of the Bisenzio River was created to feed the gualchierae (pre-industrial textile machines).
After a siege in 1107 by the troops of Matilde of Canossa, the Alberti retreated to their family fortresses in the Bisenzio Valley: Prato could therefore develop as a free commune. Within two centuries it reached the number of 15,000 inhabitants, spurred in by the flourishing textile industry and by the presence of the Holy Belt relic. Two new lines of walls had to be built in the mid-12th century and, respectively, from the early 14th century. In 1326, in order to counter the expansionism of Florence, Prato submitted voluntarily under the seigniory of Robert of Anjou, King of Naples. However, on February 23, 1351 Joanna I of Naples sold the city to Florence in exchange of
