The reign of Alexius might have been counted a period of success and prosperity if it had not been for two considerations. The first was the rapid decline of Constantinople as a commercial centre, which was brought about by the Crusades. When the Genoese and Venetians succeeded in establishing themselves in the seaports of Syria, they began to visit Constantinople far less than before. It paid them much better to conduct their business at Acre or Tyre than on the Bosphorus. The king of Jerusalem, the weakest of feudal sovereigns, could be more easily bullied and defrauded than the powerful ruler of Constantinople. In his own seaports he possessed hardly a shadow of authority: the Italians traded there on such conditions as they chose. Hence the commerce of the West with Persia, Egypt, Syria, and India, ceased to pass through the Bosphorus. Genoa and Venice became the marts at which France, Italy, and Germany, sought their Eastern goods. It is probable that the trade of Constantinople fell off by a third or even a half in the fifty years that followed the first Crusade. The effect of this decline on the coffers of the state was deplorable, for it was ultimately on its commercial wealth that the Byzantine state based its prosperity. All through the reigns of Alexius and his two successors the complaints about the rapid fall in the imperial revenue grew more and more noticeable. This dangerous decay in the finances of the empire was rendered still more fatal by the political devices of Alexius, who began to bestow excessive commercial privileges to the Italian republics, in return for their aid in war. This system commenced in 1081, when the Emperor, then in the full stress of his first Norman war, granted the Venetians the free access to most of the ports of his empire without the payment of any customs dues. To give to foreigners a boon denied to his own subjects was the height of economic lunacy; the native merchants complained that the Venetians were enabled to undersell them in every market, owing to this exemption from import and export duties. Matters were made yet worse in 1111, when Alexius bestowed a similar, though less extensive, grant of immunities on the Pisans.