The High Middle Ages in Italy, 1250-1409, were a time of incessant strife between rival city-states, some the Ghibelline allies of the Holy Roman Empire, others joining forces with the Guelph armies of the Papacy. Mercenary captains led hired bands of soldiers of fortune. These captains sometimes became great despots, ruling the very cities that had engaged them. Florence began her ascent. The terrible Visconti dominated Milan, and Genoa established a vast trading empire, only to suffer defeat and decline when her fleet was destroyed by Venice, the Queen of the Adriatic.