THE ITALIAN CITIES 345 and she largely controlled the fur trade and grain trade and slave trade by way of the Black Sea. In pursuance of her steadfast policy to center all trade in Venice and to bring as many goods there as possible, she would not allow foreign vessels to cross directly between the east and the west shores of the Adriatic, but forced them to go by way of Venice and unload at least two thirds of their cargoes there. Venetian subjects outside the city were required to do all their importing and exporting through that port. German merchants who visited Venice, besides being disarmed and subjected to strict regulations, had to dispose of their entire stock there. No import duties were levied upon certain wares which Venice wished to secure from the regions pro- ducing them in order to sell again at a profit to other places. Such goods, however, if they came by sea, must come in Venetian bottoms if they were to escape taxation, for Venice had no mind to encourage the shipping Navigation of other towns. Since she desired the carrying laws trade for herself, she naturally enacted laws favoring her own shipping and sailors. In some instances she did not allow foreign vessels to enter her harbor at all; in other cases they were taxed heavily for the privilege. In the mid- dle of the thirteenth century laws were made forbidding Venetians to ship their goods in foreign bottoms or to sell their vessels to foreigners. All vessels used by Venetian merchants must be built in Venice and manned by either Greeks or Venetian subjects. The city government built and armed the ships and then rented the use of them to the merchants. At that time it was usual to arm merchant vessels which ventured on long voyages, since there was constant danger from pirates and sometimes from the ships of Medieval rival powers. Many different types of vessels shl PP in s were employed by the medieval Italians, and they were propelled both by sails and oars. They were often built with bulging sides in order to accommodate more cargo. How- ever, the laws of Pisa, Genoa, and Venice not only forbade the heaping-up of excessive freight on deck, but ordered
