350 THE HISTORY OF MEDIEVAL EUROPE emperors and the communes and the Papacy. As a result the rival parties in Italy eventually received the names of "Guelfs" and "Ghibellines." The latter word was an Italian corruption from Waiblingen, a German estate of the Hohenstaufen family, and "Guelf " is, of course, the Italian for "Welf." In recent wars among the Lombard cities Milan had gained a leading position and other communes complained of Frederick's her aggressions to Frederick, both before he left tionto Pe l " Germany and when, in 1154, he passed through Ital >' northern Italy on his way to Rome to be crowned. The great feudal lords and the bishops had complaints to make of other communes. Frederick accordingly spent most of the autumn and winter in Lombardy, but it took him two months to take the town of Tortona, an ally of Milan, so that he had no time left to attack Milan itself and soon proceeded on his way to Rome. As soon as he had de- parted, the Milanese rebuilt Tortona, strengthened their own fortifications, and resumed their conquests at the ex- pense of those of their neighbors who had sided with the emperor. At Rome Frederick helped the pope suppress a revolutionary movement of the townsmen, who as early as 1 143 had formed a commune with a patrician and senate of their own choice instead of the papal prefect and judges. Frederick was also crowned emperor, but then distrust began to arise between him and the pope. Frederick's vas- sals were now anxious to return home after their long absence from Germany, so that he had to give up the idea of proceeding against the Normans in southern Italy. Nor did he stop to deal with Milan on his return north, although he pronounced the ban of the Empire upon that refractory city. But in 1 1 58 Frederick's German hosts poured through the Second Alpine passes by four different routes into the and^lpku- plain of Lombardy. The feudal lords of northern jation of Italy contributed contingents to his army and even the communes dared not do otherwise. Milan was soon forced to surrender, and agreed, in addition
