In the course of the wars which followed, the family of La Torre became very potent in that city, and their reputation increased so long as the emperor possessed little authority in the province.
But Frederick II.

coming into Italy, and the Ghibelline party, by the influence of Ezelin having grown powerful, seeds of the same faction sprang up in all the cities.

In Milan were the Visconti, who expelled the La Torres; these, however, did not remain out, for by agreement between the emperor and the pope they were restored to their country.
For when the pope and his court removed to France, and the emperor, Henry of Luxemburg, came into Italy, with the pretext of going to Rome for his crown, he was received in Milan by Maffeo Visconti and Guido della Torre, who were then the heads of these families.

But Maffeo, designing to make use of the emperor for the purpose of expelling Guido, and thinking the enterprise not difficult, on account of the La Torre being of the contrary faction to the imperial, took occasion, from the remarks which the people made of the uncivil behavior of the Germans, to go craftily about and excite the populace to arm themselves and throw off the yoke of these barbarians.

When a suitable moment arrived, he caused a person in whom he confided to create a tumult, upon which the people took arms against the Germans.