In northern Italy the fourteenth century witnessed the final struggle between the two great maritime republics, [Sidenote: Venice and Genoa.] Venice and Genoa. Ever since the beginning of the Crusades they had been rivals for commercial and political ascendency in the Levant. At first the advantage had been on the side of the Venetians, and the diversion of the Fourth Crusade in 1204 to attack the Eastern Empire had given them a dominant position in the islands and coasts of the Ægean. But the Genoese had their revenge in 1261, when they aided to overthrow the Latin Empire, and to establish Michael Palæologus in Constantinople. As a reward for their services they received the suburb of Pera with the fortress of Galata, whence they could dictate to the occupants of the imperial throne. The control of the straits enabled them to assume a virtual monopoly of the trade of the Black Sea, and their port of Caffa in the Crimea became one of the most flourishing cities in the east. Pisa, which had once been the equal or even the superior of Genoa, lost all maritime importance after the battle of Meloria (1284). For the next century Venice and Genoa contended on fairly equal terms. In wealth and maritime power they were evenly matched. Genoa had most of the northern trade that passed through the Black Sea and Constantinople; but Venice, which retained possession of Negropont, Crete, and other islands, had the advantage in the other two channels of eastern trade, through Asia Minor and Egypt. Genoa, however, was ready to seize any opportunity of contesting this southern trade with her rival. The occupation of Chios gave her a valuable port in the Ægean. Cyprus, which became an important commercial centre after the fall of Acre (1291), was the scene of many conflicts between the two republics. The people and the ruling house of Lusignan were in favour of Venice, but the Genoese went to war to secure their interests, and the seizure of Famagusta in 1373 gave them for some time the upper hand in Cyprus. On the African coast they also succeeded in establishing trade settlements. Farther west, the Genoese had several things in their favour. The occupation of Corsica gave them a great addition of maritime strength, though their dispute with Aragon for the possession of Sardinia exposed them to the enmity of the Catalans, who ranked after Venice and Genoa as the third naval power in the Mediterranean. On the mainland the mountains which confined Genoa to a narrow strip of coast, and prohibited territorial expansion, served also to protect her from continental enemies. Venice, on the other hand, ever since the war with Mastino della Scala had given her territories on the mainland, was exposed to the hostility of her neighbours, especially the kings of Hungary and the lords of Padua. If these states were allied with Genoa, Venice ran the risk of being cut off from supplies both by sea and land. As against this balance of strength in east and west,