Leopold took such advantage of the quarrels between the petty princes in upper Italy that he soon checked the designs of the powerful republic of Venice. His father-in-law Visconti was of great service to him in this. The predecessors of Visconti had established their power when the Lombardy League was swallowed up in a multitude of petty sovereignties. The masters of Milan at this time, Bernabo and his brother Galeazzo the Second, needing brave soldiers for their wars of conquest, many young men of the mountain country organized into troops which were granted special privileges because of their loyalty to the Viscontis. The two Milan lords were excellent army leaders but tyrannical toward their subjects. At last they became so bold as to take up arms against Pope Gregory the Eleventh, for which they were excommunicated. At the same time the Pope forbade these young mountaineers to render service to them. They recognized the papal authority and most of them returned to their homes.