Towards the middle of the 12th century, Milan had conquered for herself a powerful supremacy throughout all of Upper Italy, and with the exception of the proud Genoa and the maritime Venetian republic, all the cities of Lombardy acknowledged her sovereignty. Lodi, Pavia, and some few of the neighboring towns, had made bold attempts to assert their rights, but all their efforts were unsuccessful; and had only resulted in riveting more tightly their fetters, while the pride of the Milanese, and a desire for more extended power, increased in proportion to the failing strength of their...