Their right to share in the election of the Consuls had been long conceded, and some among them had even taken a place in that august body. In 1198 they had acquired the strength of union and organisation by forming themselves into an association calling itself the _Credenza di Saint Ambrogio_, with elective magistrates and officers of its own, and a certain share in the government and the revenues of the community. This body consisted of the lesser trades and guilds, but excluded the mass of poorer artisans and labourers. The merchants, bankers, traders in wool, etc., had their corporation also; the lesser nobles were banded in a society called the _Motta_, and the great nobles formed the _Società dei Gagliardi_, so that no less than four _factions_ existed in Milan at the opening of the thirteenth century, besides the populace, which threw its weight on one side or another, with the quick inconsistency of irresponsibility and impulse. Each faction had its separate claims and ambitions, but the tendency of the three lower ones was to unite against the great nobles, who, amid continual uproar and conflict, were gradually stripped of their exclusive power and privileges. And in 1258 the last and most sacred enclosure of their caste was stormed and carried by the Vulgar: a decree of the Republic threw open the highest offices of the Ambrosian Church to plebeians. The twelfth and thirteenth centuries were, in fact, the Epoch of the People, and though all classes, high and low, fought loyally together against Barbarossa and Frederick II., it was the democratic preponderance in the city which determined its steady opposition to the imperial pretensions. The same principle threw Milan on the Guelf side, which she upheld with ardour in the general Lombard warfare, manifesting her party zeal especially in a fierce intermittent war with Pavia. That city was as necessarily Ghibelline, though the party cry on either side was but the excuse for the efforts of the one to hasten and the other to delay the inevitable absorption of the lesser by the greater.