The Venetian–Genoese Wars were four conflicts between the Republic of Venice and the Republic of Genoa which took place between 1256 and 1381. Each was resolved almost entirely through naval clashes, and they were connected to each other by interludes during which episodes of piracy and violence between the two Italian trading communities in the Mediterranean Sea and the Black Sea were commonplace, in a "cold war" climate.
Starting in the 11th century, Venice and Genoa had built commercial empires which, in the 13th century, became thalassocracies so solid as to oust the other maritime republics and to make the two cities privileged interlocutors of state structures such as the Byzantine Empire, the Kingdom of Hungary, etc. In the second half of the 13th century the tensions between Venice and Genoa, exacerbated by the Venetian control over Constantinople following the Fourth Crusade, exploded. The first conflict, known as the War of Saint Sabas (1256-1270), was a Venetian victory, though it did not undermine the growing Genoese power in Constantinople and the Black Sea. The second conflict (1294-1299) recorded a revenge for the Ligurians, with significant military victories. After a temporary alliance against the Mongols during the siege of Caffa (1346), Venice and Genoa clashed again in the War of the Straits (1350-1355), during which Venice dragged in the Crown of Aragon, Genoa's emerging Tyrrhenian rival. This third war again ended in stalemate with a Genoese military victory at great cost. The fourth conflict, the War of Chioggia (1377-1381), saw Venice surrounded by various fronts, with the Genoese reaching the entrance to the Venetian Lagoon, but, with an enormous war effort, Venice achieved the final victory, saving the city from destruction, even without a debilitating economic outlay. Acts of piracy between the Venetians and Genoese (subject to French control in the meantime) continued until the Venetian victory at the Battle of Modon (1403). Thirty years later, the two republics faced each other again in the Battle of San Fruttuoso (1431), but in the context of the Wars in Lombardy and with Genoa then subject to the Visconti of Milan.
The real cause of the truce between Venice and Genoa starting in the 15th century was their involvement in systematic conflicts with other powers: for Genoa the confrontation with Aragon, then concluded by the subjugation of the Genoese to the Kingdom of Spain in the 16th century; for Venice the exhausting, centuries-old conflict with the Ottoman Empire. In general, the Ottoman threat to trade and the coasts of the entire Mediterranean, especially thanks to the alliance between the Sultan of Istanbul and the Barbary pirates, favored the rapprochement and collaboration between the two ancient rivals, e.g. in the Battle of Lepanto. At the same time, the decline in the share of world trade passing through the Mediterranean during the Age of Discovery thwarted the Italian republics' ambitions for commercial dominance and the resulting tensions. Despite a significant Genoese military superiority, this series of wars damaged the resources of both sides, leading Genoa into a long series of internal struggles, to the advantage of its neighbors.
Background
The economic recovery that occurred in Europe starting from the 9th century, combined with the insecurity of land communication routes, meant that the main trade routes developed along the coasts of the Mediterranean Sea: in this context, and given the crisis of the central powers, some port cities of the Italian Peninsula were able to acquire ever greater autonomy, to the point of playing a leading role in the European scenario. The traffic of these cities reached Africa and above all Asia, effectively inserting itself between the Byzantine and Islamic maritime powers, with which a complex relationship of competition and collaboration was established for the control of the Mediterranean routes. The Crusades offered these cities, the so-called maritime republics (Amalfi, Genoa, Venice, Pisa, Ancona and Ragusa) the opportunity to expand trade, which was already active, with the Levant: thousands of inhabitants of these cities flocked to the East, creating warehouses, colonies and commercial establishments, supporting the Crusaders both logistically (e.g. the Genoese supplied the troops of Bohemond of Hauteville engaged in the Siege of Antioch) and with the supply of soldiers and military support.
During the 12th century, it was the Republic of Venice (an "excellent" commercial interlocutor of Byzantium since the so-called Chrysobull of 1082) and the Republic of Genoa that emerged as dominant powers among the maritime republics, creating true and proper thalassocracies across the Mediterranean. At the beginning of the 13th century, the Mediterranean political-commercial balance was undermined by the Latin conquest of Constantinople (1204) during the Fourth Crusade which made Venice the undisputed master of trade with the East, which by then had extended, in that period, to the Black Sea, a commercial hub along the Silk Road.
In March 1261, the Byzantine-Nicene emperor Michael VIII Palaiologos allied himself with Genoa to reconquer Constantinople from the Latins and signed the Treaty of Nymphaeum which granted the Genoese important commercial privileges in the Black Sea and the Mediterranean in exchange for their active support against the other Latin powers and, above all, Venice. Constantinople was liberated from the Latins on the following 25 July and Genoa was able to establish itself there, then extending its influence into the Black Sea, where it reached Pontus (northern Anatolia) and the Crimea, while Venice was formally expelled (although the Venetian quarter of the metropolis continued to be used and populated).
This first open clash between Venice and Genoa, which originated well before the Byzantine reconquest of Constantinople and due to the inevitable collision between the two thalassocracies, came to be known as the War of Saint Sabas and was the prelude to a conflict that dragged on with alternating events until the threshold of the 15th century.
Battlefield
The Venetian-Genoese clashes usually took place off the coasts and trading posts that the two maritime republics controlled both along the Italian Peninsula and elsewhere in the Mediterranean and Black Seas.
Venice had built the foundations of its commercial empire thanks to the Chrysobull of 1082, establishing itself in Constantinople, Athens, Thessaloniki, Thebes, Antioch, Ephesus as well as in the islands of Euboea and Chios. In 1204 it considerably extended its area of influence in the Mediterranean following the capture of Zadar, the subsequent annexation of Dalmatia and the sack of Constantinople by the Crusaders. In the arrangement among the crusaders regarding the distribution of conquered territories, the Partitio terrarum imperii Romaniae, the Venetians received (in theory) three-eighths of the Byzantine Empire, including three-eighths of the city of Constantinople itself. Venice subsequently renounced part of its territorial claims, believing that control of the commercial centers and trade routes that crossed the former Byzantine Empire was more essential. In addition to its positions on the mainland, Venice took advantage of the Byzantine weakening to take control of several Greek islands: in the Cyclades, where the Duchy of Naxos was founded (1207); in Crete (1209), where the Duchy of Candia was founded; and in the Ionian Islands (Corfu, Lesbos, Kythira, etc.). The management of these territories was "mixed": in Constantinople, power was centralized in the hands of a podestà who was responsible, theoretically, for everything that happened in Romania; in the Aegean, as anticipated, Venice preferred to enfeoff its nobles and citizens by creating a network of vassalage on the model of what was done by the French Christian potentates with whom it had collaborated in the Fourth Crusade.
Genoa established itself as a maritime power following a series of victories against the Republic of Pisa between 1118 and 1131. In 1191 it took possession of Monaco, over whose currently independent principality the Genoese Grimaldi family still reigns. Following the Treaty of Nymphaeum (1261) with the Byzantines, Genoa gained access to the Black Sea, where it established several trading ports around the Crimea (e.g. Gazaria), whose main port, Caffa, was founded around 1266, a stable settlement in Constantinople in the district of Pera and others in Anatolia: in the cities of Phocaea and Scalanova (current Kuşadası) on the Mediterranean side, Trabzon, Amasra and Sinop on the Black Sea side. In 1284 Genoa took possession of Corsica and part of Sardinia following the victory against Pisa in the Battle of Meloria (in which the Pisan fleet was commanded by a Venetian, former consul of Constantinople Alberto Morosini). Like Venice, Genoa also managed these territories with an approach that favored, in the most important strategic-commercial hub (in this case the Crimea), a management consistent with the democratic regime of the city while in the Aegean there was massive recourse to the enfeoffment of citizens who personally built the overseas dominion of the republic. Compared to the Venetians, however, the Genoese were free, in the 14th century, to create real potentates with great autonomy with respect to their homeland, due to the intrinsic characteristics of the Genoese municipality, which lacked the widespread state presence of Venice.
Conflicts 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.Lane (1973), pp. 73–75
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.Lane (1973), pp. 75–76 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.Lane (1973), pp. 76–77
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.Lane (1973), pp. 77–78 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