War of Saint Sabas The first large-scale conflict between Genoa and Venice, named the War of Saint Sabas, dates back to a few years before the Byzantine reconquest of Constantinople. It originated from a dispute between merchants in
Acre (then the capital of the
Kingdom of Jerusalem since the
Holy City had been reconquered for the Muslims by
Saladin), a key business center for all trade and interests, especially Italian, in
Levantine coast. Futile reasons, actually fueled by old grievances that had excluded the Genoese from the division of the Byzantine lands after the
Fourth Crusade, led to a Genoese attack on the Venetian district of Acre. The Venetians, together with
Pisans and
Provencals, the
Knights Templar and some of the local nobility, turned against the
Catalans, the
Anconitans, the
Knights Hospitaller, other local nobles and the Genoese. A fleet sent from Venice under Lorenzo Tiepolo in 1257 defeated a Genoese fleet off Acre when it arrived in June of the following year. In 1261, with the signing of the
Treaty of Nymphaeum between Genoa and the
Nicaean emperor
Michael VIII Palaiologos, the reconquest of Constantinople from the Latins supported by Venice took place, as anticipated. On the maritime side, the
Venetian navy maintained its dominance in battle over the Genoese. The major battles that occurred, at
Acre in 1258, at
Settepozzi in
Euboia in 1263, and off
Trapani in
Sicily in 1266, were crushing Venetian victories. The Genoese instead concentrated on attacks on Venetian commercial convoys with acts of piracy as in the
Battle of Saseno. The disputes between the Genoese and Emperor Michael VIII allowed the Venetians the possibility of having commercial privileges in the Byzantine Empire, with a
truce signed in 1268. The war ended in 1270 with the
Peace of Cremona, mediated by
Louis IX of France and
Pope Clement IV who wished to organize the
Eighth Crusade and needed the Venetian and Genoese fleets for this undertaking. Following the peace, Venice increased its power in what remained of the Kingdom of Jerusalem but was unable to prevent the relaunch of Genoese trade in the Byzantine world and the establishment of their commercial dominion in the Black Sea which would last until the
Ottoman conquest of Constantinople (1453).
War of Curzola The continuous rivalry between Venice (which in 1277 had managed to re-enter the Byzantine political orbit by settling in
Thessaloniki) and Genoa led to clashes in 1291 and the resumption of war in 1295. In 1294, at the Battle of Laiazzo, a Venetian fleet was destroyed by a naval fleet from Genoa's eastern colonies off the important port of
Laiazzo, in the
Armenian Kingdom of Cilicia. Subsequently, the Venetians rebuilt a fleet that sacked the Genoese ports of Phocaea in the Aegean, Caffa in the Crimea, and Pera (then unwalled) in Constantinople. In retaliation for the sack of Pera, the Genoese of Constantinople attacked the local Marciano neighborhood, massacring its inhabitants. Despite the Byzantine-Venetian truce of 1285, the Byzantine emperor
Andronikos II Palaiologos immediately sided with the Genoese, arresting the Venetian survivors of the massacre, including
bailo Marco Bembo. In July, the Venetian fleet, under the command of Ruggiero Morosini Malabranca, stormed the Bosphorus. During the expedition, various Genoese possessions in the Mediterranean and Black Sea were captured and plundered, including again
Phocaea and Pera. The
basileus, however, preferred at that point to avoid siding with Genoa again to avoid a war with Venice. In 1298, the Genoese fleet under the command of
Lamba Doria entered the Adriatic and engaged the Venetians in the bloody
Battle of Curzola, the largest and most challenging maritime clash between the two republics to date. The Venetian fleet, under
Andrea Dandolo, was destroyed. The Genoese had also suffered serious losses and decided to return home rather than advance towards Venice. It was during this battle, according to some in Curzola and according to others in Laiazzo, that the famous Venetian
Marco Polo was taken prisoner and while in prison he wrote his memoirs. In 1299 with the Treaty of Milan the two Republics signed peace. The Venetians instead continued the war with the Byzantines.
Interlude: Fights against the Turks and Mongols At the beginning of the
14th century, relations between Genoa and Venice were still in a state of tension (in 1304 the Genoese occupied
Chios with the approval of Byzantium) but the political upheavals in Crimea managed to make the two thalassocracies unlikely allies. On the Black Sea, relations between the Mongols and Italian merchants were somewhat ambiguous: the Mongol knights, averse to the sea, benefited from the Italian trade that connected Asia and Europe through the Crimea but the enrichment of the European trading posts fueled their greed. From 1307 tensions emerged on the issue of the trade in Turkish slaves, sold by the Italians to the
Mamluk Sultanate of Egypt to make them soldiers. Dissatisfied with this trade fueled by steppe kidnappings to provide an army to his enemy the Mamluks,
Khan Toqta of the
Golden Horde arrested the Genoese residents of Sarai Berke and besieged Caffa. Poorly protected by an earth and wood fence, the city fell in May 1308 and was abandoned by the Genoese who set it on fire. When Toqta died in 1312, Genoa sent ambassadors to his successor,
Özbeg Khan, who agreed to welcome the Genoese back and in 1316 adopted measures to encourage the reconstruction of Caffa. In 1327, Venice began to push for the formation of an anti-
Turkish league including Byzantium, the Knights Hospitallers and the lord of Chios, to put a brake on the growing power of the
Turkish Beilicates of Anatolia (in 1320, Smyrna, already Genoese, had been conquered by the
Turkish emir of Aydin). The league faced and defeated the Turkish fleets in the Battle of Adramyttium (1334) and then supported the Anatolian expeditions of
Hugh IV of Cyprus (1336-1337). The subsequent Christian expeditions, known as the Smyrna Crusades (1343-1351), managed to bring some order to Anatolia, giving the Venetians respite from the Turkish threat. In the meantime, after the death of Özbeg Khan in 1341, his son
Jani Beg reignited tensions between the Mongols, recently converted to
Islam, and the Italians in Crimea. In 1343, a Mongol merchant was killed during an altercation with a Venetian nobleman in the city of Tana, and in retaliation, the Horde attacked the Venetian exercises in Tana, giving Jani Beg the pretext to assume control of all Italian trading posts, while the Genoese took advantage of the Venetian withdrawal from Tana to establish a commercial monopoly in the Black Sea. In 1346 Jani Beg attacked Caffa. After two years of siege, the Mongols were forced to retreat after being decimated by the
plague, which also infected the Genoese after Jani Beg decided to throw plague-ridden corpses over the city walls. Following this act of
bacteriological warfare, the
epidemic rapidly spread to Caffa, most likely from rats making their way into the city rather than because of the flung corpses, and forced the Genoese to abandon the city after the siege was lifted by the Mongols. The dispersal of Italian merchants in the Mediterranean, with their ships carrying
flea-infested
rats, was the cause of the second plague pandemic in Europe, the "
Black Death".
War of the Straits Disputes over Black Sea prompted the outbreak of another war in 1350, in which Venice allied with
King Peter IV of
Aragon, who was at odds with Genoa over control of
Sardinia and the commercial rivalry between his
Catalan subjects and the Genoese, and entered the war in 1351. Following clashes between local forces in the Aegean and around the
Bosphorus, in 1351 a major Genoese fleet under Paganino Doria
besieged the Venetian colony of
Negroponte before advancing to Constantinople. The Byzantine Emperor
John VI, who had lost a
short war with the Genoese in 1348–1349, had been induced to enter the war on the Venetian side and assisted them in attacks on Pera. A combined Venetian-Catalan fleet under Niccolo Pisani and the Catalan Ponce de Santapau arrived soon afterwards and joined forces with the Byzantines, and the bloody
battle of the Straits was fought in the Bosphorus in February 1352. Both sides suffered heavy casualties, but the most serious losses were inflicted on the Catalans, inducing Pisani to withdraw and enabling Doria to force Byzantium out of the war. In August 1353, Pisani led the Venetians and Catalans to a crushing victory over the Genoese under Antonio Grimaldi off
Alghero in Sardinia. Alarmed by the defeat, Genoa submitted to
Giovanni Visconti,
Lord of Milan, in order to secure his financial support. In 1354 Paganino Doria caught Pisani unprepared in his anchorage at
Zonklon (Sapienza) in the
Peloponnese and
captured the entire Venetian fleet. This defeat contributed to the deposition of doge
Marino Faliero, and Venice made peace with Genoa on 1 June 1355. Though inconclusive in itself, Venice's exhaustion by this war helped bring about the loss of
Dalmatia to
Hungary shortly afterwards. Freed of the need for support from Milan, the Genoese brought an end to Milanese rule in 1356.
War of Chioggia In 1376 Venice bought the strategically positioned island of
Tenedos near the
Dardanelles from the Byzantine Emperor
John V, threatening Genoese access to the Black Sea. This induced the Genoese to help John's son
Andronikos IV to seize the throne, in return for the transfer of the island to Genoa, initiating a new war between the two republics. The Genoese failed to take Tenedos from the Venetians in 1377, but gained the support of a coalition of Venice's mainland rivals Hungary,
Austria,
Aquileia and
Padua, although only Padua gave substantial assistance. Venice allied with Milan, whose army threatened Genoa from the landward side, and with the
Kingdom of Cyprus, which had been defeated in a war with Genoa in 1373-74 and subjected to Genoese hegemony. A small Genoese fleet led by Luciano Doria invaded the Adriatic in 1378 and defeated the Venetians under Vettor Pisani at
Pula in 1379. Having been reinforced, they advanced against Venice under Pietro Doria, Luciano having been killed at Pula. Though failing to break through the defences of the Venetian lagoon, the Genoese captured the port of
Chioggia near its southern end, with support from the Paduans on land. In December 1379 the Venetians were able to sink blockships in the harbour of Chioggia, trapping the Genoese fleet inside. Venice was reinforced by the return of a raiding fleet under Carlo Zeno, which had enjoyed exceptional success against Genoese commerce throughout the Mediterranean. A new Genoese fleet was assembled in the Adriatic, but was unable to break through to relieve Chioggia. The forces trapped inside were forced to surrender in June 1380. Fighting continued between the Genoese and Venetian fleets over the ports of the upper Adriatic, but through the mediation of
Amadeus VI of Savoy, the two sides negotiated
peace at Turin in 1381. Despite the victory at Chioggia, the war had been financially disastrous for Venice, which only secured peace by agreeing to concessions including the evacuation of Tenedos, recognition of Genoese supremacy in Cyprus, the surrender of its principal mainland possession of
Treviso, and the payment of an annual tribute to Hungary, whereas Genoa and its allies made no significant concessions. ==Disengagement==