The city-state was pretty much a monarchy de facto if not in name until the 11th century as the position of doge was passed on from father to son, establishing dynasties. There certainly was a popular assembly, but it was to be consulted by the doge at his will, and nothing required that he listened to their opinion, even if it was formally that assembly that elected the doge. However, even at this early stage, there was an opposing force to that of the doge: the venetian aristocracy. The members of this elite not only had pretentions because their origins dated back all the way to the foundation of the city, but because, thanks to trade, they'd also become immensly rich. They were already occupying the highest positions in the city and were those who, in fact, elected the new doge. But they wanted more: they were a conservative force that wanted power for itself, in the form of an oligarchy. In that sense, its action on venetian politics would be twofold: on one hand, it would oppose the doge when he would threaten to increase its power, and the resolution of the subsequent conflicts would often be found in violence and murder; it would also oppose him in less noticeable ways that would however contribute to the erosion of his power. Also, progressively, it would diminish whatever power the popular assembly originaly held.

One of the first legal manifestation of that long-term strategy of the aristocracy happened in 1032: when the dynasty of the Orseoli ended, the first constitutional law of the city-state was passed, forbidding the doge to choose a co-regent. This was a way to put a end to the inheritance of the title from father to son. At the same time, two counselors of the doge were appointed (who would later be six), whose role was as much to watch his moves as to assist him in his tasks. But, if one were to believe the venetian chronicles written during the 16th and 17th centuries, it is really between 1172 and 1179 that the whole political balance shifted. However, history shows that changes weren't that swift.

During the 12th century, dramatic political changes occured throughout Italy, and the people lost power to the aristocracy in most cities. In Venice too, such changes occured, although the doge was stripped of most of his power long before the popular assembly. From 1148, the doge had to make a constitutional promisso, i.e. take an oath, and the text was written by a commission that was careful to diminish each time the personal power of the Doge. When Enrico Dandolo took his oath in 1192, his power was already limited to the leading of the army in times of war; besides that, everything depended on a Greater Council; there was also a Lesser Council holding the executive power. Indeed, in 1143, the nobles from Rialto had created the comune Veneciarum that pretended to intervene in the doge's poltics, at the exclusion of all other families, even noble, of the city; parallely, a council elected by the different neighborhoods of the city, the Sapientes, became a permanent council to the doge. 50 years later, they evolved into the Greater and the Lesser Council respectively, whose members were elected by the most important families of the city. Numerous commissions were created, among which one that would become the Quarantia (1223) and another, a spin-off of the Lesser Council, would later become the Senate. The people the doge had sometimes gathered around him for their opinon, named Pregadi, would become part of the latter once they were appointed by the Greater Council, and not summoned by the Doge anymore.

At the beginning, and until 1297 and the serrata del Consiglio, the Great Council was, in theory, open to all citizens, and each family couldn't be reprensented by more than four members. It was also, in theory, elected by the popular assembly. However, it was quickly dominated by a small number of noble families. But the people wanted to get their right to elect the doge themselves back (the doge was, at the end of the 13th, elected by the Great Council through a long and tedious process). In order to secure their power and keep it from the versatile population, the Great Council succeeded in electing as new doge an important member of the aristocracy, Pietro Gradenigo, who proposed the famous serrata del Consiglio, the "closing of the Council". Although the number of seats at the Great Council was expanded, the possibility for someone from outside the venetian aristocracy to become a member of that council was greatly reduced, before being completely abolished when it was decided that only those from families who had had at least a seat at the Great Council since 1172 could pretend to one for themselves. However, within that elite, it was decided that all would be equal, in order to maintain the solidarity among the governing houses. Since 1297, that cast of leaders would open its doors to new men only exceptionally.

The Great Council had become too big to play a decisive role in the sometimes grim task to protect the system from those unhappy with it, but an attempted coup was about to give it the occasion to create another small yet extremely powerful body that would do just that: the Council of Ten. In 1310, a conspiracy led by Bajamonte Tiepolo was thwarted almost at the last minute, and all those behind that coup were either executed or exiled. But there was still unrest: to investigate and thwart any other attempt against the Republic, and to restore peace, a commission of ten was created for three months, with no more than one member from any given family. They had emergency powers, and could act in secret. They were so successful that their mandate was renewed until 1334, when it became a permanent body, known under the name of Council of Ten (that name remained although were also present at the daily sessions the Doge and his six personal counselors. For a detailed presentation of the Council, see that article. It proved very efficient for instance at the occasion of the coup ploted by the doge himself, Marino Falier, in 1355, at a time when the difficulties of Venice in its war against Genoa led to malcontentedness and unrest. But the conspiracy was brought to the ears of the Ten, and all the men behind it were arrested, went through a trial and were executed. This was the last major attempt at disturbing the government for a while.

To follow: The Consitution and governance in Venice, part two: the organization of the government