It was only towards the end of the tenth century (after having briefly been a small centre of the marquisate of Friuli) that Treviso became the capital of the Trevisan Marca, which in 1162 was identified in the motto "Monti Musoni Ponto dominorque Naoni" (dominion from the mountain to the sea, from the Musone to the Noncello). This motto is still used today in the coat of arms of the Provincial Administration.

THE BIRTH OF A CITY·STATE

Meanwhile, the first seeds of associative life were being sown, forming the City of Treviso. The main protagonists in this were the vassalli minori, house and land owners, who moved within the city in order to better follow its economic and commercial development. From these were chosen the "boni homines", or arbiters, who were increasingly invited to take active part in bartering, sales, investitures etc., as representatives of the citizens, while maintaining the "giurisdizioni primitive", or basic justice systems which remained the appanage (or revenue) of the Emperor, Marquis, Count, Bishop ..
It was, however, a slow process of evolution: a society made up of diverse extraction (Roman, Longobard, Salian, German) trying to take control of its public life through its leading citizens. One must recognise Federico Barbarossa in this struggle. It was he who, in 1164, granted the city a series of privileges, exemptions, and immunities that were, most importantly, an acknowledgment of Treviso as a city state: the right to fortify the city; freedom to construct houses with porticoes; exemption from general taxes and the heavy mill taxes etc .. Despite these concessions from Federico Barbarossa, the city soon rebelled, crushing the imperial Vicari and taking part in the general assembly at Pontida on December 1, 1167. Treviso supported the ensuing battles undertaken by the Lega against the Emperor until the treaty of Constanza was signed on June 25, 1183. Treviso was thus able to claim independence, raising its own flag - a white cross on a red background flanked by two eight-pointed stars - on public buildings. This flag had already been replacing the old flag of three black towers on a white background.
Municipal organisation had practically been achieved and was officially codified with the first City decrees of 1162. These provided for the annual nomination of six officials with the power to make war or peace, strengthen or break alliances, administer justice, and lavish investitures. These officials were elected by the town council, a sort of mini parliament with legislative duties and composed of 100 citizens chosen at a public arengo (assembly) convened by the Mayor, the Podestà, at the sound of the large bell (called the Marangona) that still rings, at the top of the tower in Piazza dei Signori. (The Podestà appears in Treviso for the first time in 1176). There was also, of course, a whole series of subsidiary controlling bodies, officials, judges, notaries, clerks, squires etc., with clearly defined duties and wages, to administer the City. There was also a "militia" which, in times of peace, consisted of 50 cavalry soldiers under the command of a captain and at times of war, consisted of every able bodied man from the age of 16 to 60.
The statutes also defined, with rare precision, suitable punishments for those who overstepped the rules. The punishments were particularly severe and ranged from torture, decapitation, mutilation (of hands, feet, ears), and even the removal of eyes, to the stake, a punishment reserved for the most grave of wrong doings. Marchesan recounts, in his "Treviso Medioevale", that these punishments were generally executed at least three miles from the city gates, and only carried out inside the city walls when serving as an example. The torturer on duty and "notaries of crime" who, with the cart drivers and priest, had to attend, were paid on a regular basis. A surgeon was also present for amputations (a punishment based on the law of "an eye for an eye") to bandage the torn limbs. False witnesses had their noses and upper lips cut off, or perhaps their tongue cut out or an eye gouged.
However, do not think that these corporal punishments were exclusive to Treviso: by the Middle Ages they had become general practice. Even the Republic of Venice herself didn't toy with scoundrels and traitors, showing by her inflexible example how one was expected to behave in its occupied territories, convinced as the Republic was that, in certain cases, fear rather than conviction was the greater inducement to lawful behaviour.
The most serious punishments were given to deserters and traitors: once in the hands of the law they would be hung with irons in the streets, sometimes after having been quartered.
Other various events occurring between 1200 and 1230 worth noting are: the making of peace with the Patriarca of Venezia; the construction of the "domus lapidea comunis" (1207); the castello d'Amore or Castle of Love, 1214 which caused a war between the Paduans and Venetians involving the Trevisans; the arrival of the Dominican friars (church of SI. Nicolo', 1221) and Franciscan (1226) in Treviso; and the completion of the medieval walls.
Treviso had a particularly busy and dramatic historical period during the conflicts between the Guelphs (i Guelfi) and the Ghibellines (i Ghibellini) and the dominion of various squires, who contended their rights with bloody battles of conspiracy, rivalry and betrayal.

THE SIGNORY

The first "Signory", or family of Lords, began to rule the City on May 14, 1239, when Alberico da Romano betrayed his brother Ezzelino, who had left him to govern Treviso in his place. Alberico backed by Guecello and Biaquino da Camino, occupied the city, driving out the Ghibellines and the Imperial delegate who had been nominated by Federico II two years before-hand. Federico II and his troops had previously entered the city preceded by none other than the two Da Romano brothers.
Alberico was Lord of Treviso and Podestà (mayor) for almost twenty years. At first, his governing seemed good and wise, earning the praises of two popes (Gregory IX and Alexander IV). He befriended poets from Provence and was himself - so the historians tell us - a productive verse-monger. Unfortunately little evidence of this remains. According to others (Monaco di Padova) he was cruel and barbaric, surpassing even his brother Ezzelino's atrocities. It is known, however, that Alberico did in fact change after making peace with Ezzelino on April 3, 1257 (before this there had been much ill feeling between the two brothers). The reconciliation with his brother caused him to be excommunicated by the Pope for becoming a protector of the Ghibellines, who were considered heretics.