These maritime cities constantly fought one another; Pisa destroyed Amalfi, Genoa ruined Pisa, and Venice finally crippled Genoa. The glory they won was by individual effort; whereas the glory of the Lombard cities is that they effected a union, tardy indeed and imperfect, but successful at last in its purpose of enforcing their liberties against the Imperial claims. These Lombard cities included in their respective dominions the country round about, and were, in fact, except for a negligent Imperial control, little independent republics. It has been a matter of long dispute whether these communes were survivals from old Roman times, or sprung from the love of independence brought in by the Teutonic invaders; whatever their origin they virtually began with trade, rested upon trade, and flourished with trade. This trade, which, beginning between neighbouring cities, extended northward over the Alps, was greatly aided by the maritime cities. Ships called for cargoes. The stimulus imparted by the energy of Venetian, Genoese, and Pisan seamen to manufactures and transalpine trade was felt in every Lombard city. For instance, the Venetians, eager to carry a wider range of merchandise over sea to Alexandria or Jaffa, held fairs in the inland cities, exposed the wares they had fetched home, and stirred mercantile industry. A burgher class of traders and artisans grew up. Men met in the market-place, talked business, considered ways and means, discussed the conditions of production and exchange, and became a shrewd, capable class. The moment business expanded beyond the city walls, it bumped into feudal rights at every corner; at every crossroad it found itself enmeshed in feudal prerogatives and privileges. Trade could not endure a system fitted only for a farming community. Trade took men into politics; and in those days politics meant war. The citizens of Milan, Pavia, and neighbouring cities were not wholly unused to civic rights, for they had long had a voice in the election of bishops, and they had their trade guilds. These rights they enlarged whenever they got a chance; and chances came frequently in the quarrels between Emperor and archbishop, or between the greater and lesser nobility. Both sides wanted their support; and they sold it in exchange for privileges, here a little, there a little, and obtained many concessions. Finally, after the burghers had advanced in wealth and social consideration, the petty nobles made common cause with them; and the two combined succeeded in forcing the great lords to join also, and make one general civic union. These great lords, who had been little tyrants in the country roundabout, were compelled to live within the city walls for part of the year and be hostages for their own good behaviour, and were thus converted from enemies into leading citizens. The consequence of these changes was that the former government by a bishop, which in course of