Initial clashes On 6 August 1350, Venice declared war on Genoa. On the same day, a compulsory loan to finance the fleet was decreed.
Marco Ruzzini was elected
Captain General of the Sea, and set sail at the end of August for Greece with 35
galleys. Both cities had suffered heavy losses because of the
Black Death—which had come to Europe with ships from Caffa in 1348—that had depleted their citizenry: Genoa lost about 30,000 of its 60,000–70,000 inhabitants, while Venice went from 120,000 in 1338 to about 65,000 in 1351. According to the historian
Frederic C. Lane, the remaining male citizen population did not suffice for manning any more than 25 galleys, meaning that the Venetian government had to resort to conscription in Dalmatia and its
Greek possessions to fill out its fleet's ranks. In addition, the conscription of the Venetian citizens proved unpopular, and many extricated themselves by hiring substitutes. The result was that the Venetian fleet was manned by crews that were both inexperienced an indisciplined, a fact that became evident at the first battle of the war: on 17 September, Ruzzini's fleet attacked a Genoese fleet of 14 merchant galleys under
Nicola di Magnerri at Castro (), near the Venetian colony of Negroponte (
Euboea). The Venetians captured ten ships, but the inexperience and indiscipline of the conscripted crews, which abandoned the battle to plunder the captured vessels, allowed the remainder to escape to Chios. This provoked outrage at Venice, but the Venetian Senate failed to pursue the matter, realising that many of the crews were attracted by the promise of pay and booty, and were likely to mutiny if they were denied that. Ruzzini then sailed to Pera, where he conducted a brief and unsuccessful siege, before conducting a foray into the Black Sea. On his return home, he was welcomed with honours. In the meantime, however, the four galleys he had allowed to escape joined with five more Genoese ships at Chios, and, under the command of
Filippo Doria, they launched a successful surprise attack on the city of Negroponte (
Chalkis) in October, and burned its harbour, though the citadel resisted successfully. The local Venetian (governor),
Tommaso Viadro, fled the field, and was later put on trial for cowardice in Venice; he only escaped execution due to the intervention of the Doge. Neither Viadro nor Ruzzini were selected again for military commands.
Venetian alliances and Genoese reaction In spring 1351, a papal appeal to the two combatants to cease the conflict had no effect, as did a letter by the celebrated poet
Petrarch to the Doge of Venice, enjoining the two states "to lay down their uncivilized weapons, to unite their souls and their flags and to give each other the kiss of peace". Instead, the conflict expanded across the Mediterranean. The first actions of the war had demonstrated to Venice the need for much larger forces, and thus the need for allies, to make up for its own diminished human resources. As a result, Venice turned to two of Genoa's rivals: the Byzantines and the
Crown of Aragon. An attempt to secure the support of another Italian naval power, the
Republic of Pisa, was rebuffed. The Aragonese had been at loggerheads with the Genoese over
Sardinia, and despite previous confrontations with the Venetians over the activities of the Catalan rulers of the
Duchy of Athens in Greece, King
Peter IV of Aragon and his influential commander,
Bernat II de Cabrera, proved willing to enter into an alliance with Venice. The treaty, concluded at
Perpignan on 16 January 1351, was scheduled to last at first until 29 September, after which it would be renewed for four years. Neither party was to sign a separate peace. Aragon undertook to equip a fleet of 18 galleys for operations in the
Tyrrhenian Sea against a monthly payment of 12,000
florins, two thirds of which was to be paid by Venice, in exchange for one third of all spoils. A further 12 Aragonese galleys were to be rented by Venice. Kantakouzenos proved less easy to convince: the Venetians sent an ambassador,
Antonio Bragadin, to the emperor already in 1350, but the latter was preoccupied with a war against the
Serbian Empire and refused to join another conflict. In spring 1351, the Venetians sent a fleet under
Giovanni Dolfin to again attack Pera, but Kantakouzenos still hesitated, as he received reassurances from the Genoese. In response, the Venetians withdrew their ambassador from the Imperial court. Finally, the Byzantine emperor joined the war reportedly as a result of Genoese provocations, when the Genoese of Pera began catapulting rocks at Constantinople's walls. A treaty was concluded in May 1351, in which the emperor agreed to provide from 29 September 12 galleys for 10,776 per month, with Venice again providing two thirds of the sum. Further clauses stipulated the return of Imperial territories held by the Genoese. A Venetian fleet of 22 ships was sent under
Niccolò Pisani to join the Byzantines and jointly besiege Pera. On the other side of the conflict, Genoa tried in vain to dissuade both the Aragonese and the Byzantines from their alliance with Venice, arguing that Venice's promises were not to be trusted upon. With the conflict about to assume pan-Mediterranean dimensions, the Genoese government established a dedicated magistracy to run it, the . A forced loan of 300,000
liras was imposed on 25 November 1350, with its shareholders guaranteed an annual 10% interest rate. To pay for this, the proceeds from 22 taxes were repurposed. These measures allowed the Genoese to mobilize larger fleets: on 13 July 1351, sixty ships with 180 men on board each sailed from Genoa, under the command of
Paganino Doria. Nevertheless, the Genoese were unable to repeat their maximum effort during the previous conflict, when they put a fleet of 165 galleys at sea. In early 1351, the Genoese attacked the
Duchy of the Archipelago, a Venetian ally in the Aegean, captured Duke
John I Sanudo and his family, and plundered the island of
Naxos. Soon after, the Genoese concluded a treaty with the Aydinid emir which ensured the resupply of Chios from the Aydinid port of
Ephesus. At the same time, the Genoese of Pera sought assistance from their Muslim neighbour, the
Ottoman sultan
Orhan. In exchange for the payment tribute—which in Ottoman eyes made Pera a vassal territory—Orhan pledged military support, and provided 1,000 archers to serve on board the Genoese fleet and to man the walls of Pera against the Venetian and Byzantine attacks. This began a Genoese–Ottoman alliance that would last until the
Fall of Constantinople in 1453. While the Genoese secured trading privileges in Ottoman domains, and protection for Pera, the Ottomans gained an advantage that proved a crucial turning point for the
history of Europe: Genoese ships allowed them to cross the Bosporus and begin their
expansion into Europe.
Doria's expedition to Pera Doria initially tried to seek out the Aragonese fleet in the waters around southern Italy and bring it to battle, but after failing to find them turned east, towards Pera. When Grimani heard of this, he abandoned the blockade of Pera and withdrew to Negroponte, abandoning the Byzantines, whose fleet was defeated by the Genoese of Pera on 28 July. At Negroponte, Grimani scuttled his own ships to prevent them from being captured and helped man the fortifications with his men. There he was in turn
besieged by Doria until he was forced to withdraw in the face of an Aragonese fleet of forty galleys under
Pancrazio Giustinian and . The defence of Negroponte was assisted by the Catalans of the
Duchy of Athens, who sent 300 cavalry and a large number of infantry to assist the Venetians. After the Genoese left, the Venetians refloated their scuttled ships. Doria withdrew to Chios, where he replenished his forces and filled out his crews, and then sailed north. His fleet captured the island of
Tenedos on the way. At the port of
Heraclea in the
Sea of Marmara, the Genoese sailors landed to take on supplies. Fighting erupted with the locals, after which the Genoese sacked the city. Kantakouzenos, forewarned of Doria's progress, ordered all his cities to look to their fortifications, withdrew his own ships behind the protection of Constantinople's fortified harbour, and recalled his field army from
Thrace. Thus, after the Genoese arrived at Pera, they found they could not achieve much. Despite receiving support from the neighbouring Turkish rulers—Sultan Orhan and Khidr Bey—the Genoese did not press their advantage, as their supplies were limited and their objectives unclear, while Kantakouzenos awaited the arrival of his allies behind the strong fortifications of Constantinople. In November, however, the Genoese sacked the Byzantine city of Sozopolis (
Sozopol) in the Black Sea.
Battle of the Bosporus and exit of Byzantium from the war The stalemate was broken only in early February 1352, when the allied fleet arrived from the Aegean, having suffered some losses to storms. Doria tried to sally forth and engage the Aragonese and Genoese before they could join the Byzantines, but contrary winds prevented him from doing so until 13 February. The two fleets met near the
Princes' Islands, southeast of the entrance to the Bosporus. The encounter happened late in the day, leaving just two hours of light, but the Aragonese commander, Santapau, insisted on fighting. Doria was unable to prevent the union of the Venetians and Aragonese with the small Byzantine fleet, putting him and a distinct numerical disadvantage, with only 60 or 64 ships against 89 or 90 allied vessels. The ensuing
Battle of the Bosporus took place in the narrow strait and was a disorganized and bloody affair that dragged well into the night. The Venetians and Aragonese withdrew after losing 23 ships and admiral Pancrazio Giustinian, leaving the field to the Genoese, who thus gained the nominal victory, despite their own heavy losses of 16 vessels. Both sides spent the next couple of weeks recuperating, but when Doria offered battle on 3 March, the allies refused to sail out. Doria then anchored on the Asian side of the Bosporus, welcomed by Orhan, until the allied fleet left in April. Strategically, the Genoese emerged as the victors of this phase of the conflict, having managed to thwart the allies' attempt to dislodge them from their choke-hold on the entrance to the Black Sea. Abandoned by their allies, the Byzantines were forced to come to terms with the Genoese. In a treaty signed on 6 May 1352, Kantakouzenos ended the war with Genoa, prohibited Venetian and Aragonese ships from entering his ports, recognized the full possession of Pera by the Genoese, and renewed the privileges of the Treaty of Nymphaeum. The victorious fleet of Doria returned home to Genoa in August, but the heavy losses suffered meant that no triumphal welcome was staged. At the same time, the Genoese concluded an offensive military alliance against Venice with Louis of Hungary, with a duration of two years.
Conflict in Sardinia and the surviving local lordships With Byzantium's exit from the war, the focus of the conflict shifted to the Western Mediterranean. Peter IV had long seen Genoese influence on Sardinia as an obstacle to his aims to centralize Aragonese rule over it and
Corsica. As part of his preparations for a campaign there to solidify control against both the Genoese and restive local lords, in June 1352 the King of Aragon obtained the right to occupy the castle of
Osilo during wartime from its
Malaspina lords, and in January 1353 secured the submission of a few of the local members of the Genoese
Doria family by recognizing their local possessions. Other Sardinian nobles however were not so easily won over, including the
Judge of Arborea,
Marianus IV; on 15 February 1353—with the support of Marianus IV, who was also in talks with Genoa—the town of
Alghero on the northwestern part of Sardinia submitted to Genoese rule. In response, Peter IV appointed Bernat de Cabrera as his captain-general for the Sardinian expedition. At the head of a fleet of 46 galleys, 5
cogs and 6 other vessels, Cabrera sailed from
Minorca on 18 August, reaching Alghero seven days later. Cabrera arranged for a siege of the city, under the Aragonese governor of Sardinia,
Riambau de Cobrera, and sailed south to meet with a Venetian fleet of 20 galleys, under Niccolò Pisani, which had arrived at
Cagliari. On 27 August, at the Bay of
Porto Conte, just off Alghero, the allied Aragonese–Venetian fleet
inflicted a heavy defeat on a Genoese fleet of 55 ships under Antonio Grimaldi. Three days later, Alghero surrendered to Cabrera's forces. The Genoese setbacks in Sardinia caused the Doge of Genoa,
Giovanni II Valente, to resign his office. As internal tensions in Genoa raised the spectre of renewed conflict between the
Guelph and Ghibelline factions, on 9 October 1353 Genoa submitted to the rule of a foreign prince who could both protect the city and finance the war effort:
Giovanni Visconti,
Archbishop and
Lord of Milan. The Aragonese conquest proved precarious: the local governor had to suppress a Doria revolt in October, and in the next year, the city was lost again and had to be in June 1354. It was only with the capitulation of Marianus IV of Arborea in November 1354, that the city definitively came under Aragonese control, followed by the deportation of its inhabitants to the Aragonese heartlands and the
Balearic Islands, and its settlement with
Catalan colonists. The Genoese launched a privately funded attempt to recover the city in 1354 with a fleet of 15 galleys under Filippo Doria. However, rather than attempt an attack that was unlikely to succeed, and needing to repay his investors, Doria instead diverted his fleet to
Tripoli, which he sacked and held for a few months.
Doria's Adriatic raid and the Battle of Sapienza Venice reacted to the Visconti takeover of Genoa by forging alliances with the northern Italian lords:
Ludovico I Gonzaga of
Mantua,
Cangrande II della Scala of
Verona,
Giovanni Manfredi of
Faenza, and
Aldobrandino III d'Este of
Ferrara, as well as
Charles IV of Bohemia. In early 1354 (though other accounts put it as early as November 1353), Petrarch, who had good relations with Doge Andrea Dandolo was sent by the Visconti to Venice to negotiate an end to the conflict, but without success. In the same year, the Genoese equipped a fleet of 24 galleys under Paganino Doria, a far cry from the large fleets launched during the start of the war and likely indicative of the exhaustion of Genoa's human and financial resources by this stage. Doria led his fleet west and even briefly threatened
Barcelona, before turning back towards Sardinia and Alghero, while avoiding a direct confrontation with the Venetian–Aragonese fleet. Instead, he resolved to challenge Venice by sailing into the
Adriatic Sea, traditionally seen by Venice as its particular area of influence, being known as the "Gulf of Venice". Doria's fleet raided the Dalmatian islands of Lesina (
Hvar) and Curzola (
Korčula), and on 16 August 1354 sacked Parenzo (
Poreč) in
Istria, from where the relics of saints
Eleutherius and
Maurus of Parentium were taken and brought to Genoa, where they were deposited at the church of
San Matteo. The Venetians feared that Doria would attack Venice next, and placed a heavy chain to bar entrance to the
San Marco basin, while compulsory loan was levied, the population capable of bearing arms was assessed, and a force of 300 men was mobilized from each of the city's
six districts and placed under the overall command of
Paolo Loredan. Rather than attack Venice, Doria led his fleet back out of the Adriatic and east to Chios, forcing the Venetian fleet under Pisani to abandon Sardinia and follow him. Despite enjoying qualitative and numerical superiority, however, Pisani did not attack Doria at Chios, giving the latter the chance to obtain reinforcements. of Genoa In the meantime, Pisani received messages ordering him to the Venetian outpost at Coron (
Koroni) in southwestern Greece. According to some accounts, there he received instructions to avoid confrontation with the Genoese, as they were thought to have by now a superior fleet, and as negotiations for ending the conflict were ongoing, but other sources do not mention anything of this kind. Pisani in mid-October left Coron and sailed to the natural anchorage of Porto Longo, at the nearby offshore island of
Sapienza. There the Venetian admiral awaited the arrival of the Genoese fleet, which would have to pass by the area on its way back to west, placing part of his ships to block the entrance of the bay, and anchoring the rest at the shore. On 3 November 1354 Doria arrived with 35 galleys, but the Venetians did not sail out to give battle. On the next day, Doria sent part of his ships to
attack the entrance of the harbour; these broke through the Venetian resistance and forced the entire Venetian fleet to surrender. Over 4,000 Venetians were killed, and 5,400 taken prisoner, Grimani among them. While Doria returned to a hero's welcome in Genoa, Pisani, soon released by the Genoese, found himself before a tribunal, where he was accused of disobeying his instructions and negligence in command. He was condemned on 5 August to imprisonment and a fine of 1000 pounds, as well as a prohibition of further military command. He died soon after.
Peace treaty Both sides were by now exhausted. While Genoa was for the moment victorious, its Visconti masters wanted peace. When Archbishop Giovanni Visconti died, his nephews and successors,
Matteo II,
Galeazzo II, and
Bernabò lacked any interest in prosecuting the war further. Venice was increasingly pressured on its Dalmatian frontier by King Louis of Hungary, while the death of Doge Andrea Dandolo, who had promoted an anti-Visconti league in northern Italy, was followed by the discovery of an
abortive coup by Grandenigo's successor, Marino Faliero, supported by discontented commoners, in April 1355. With the mediation of the Visconti lords, a peace was signed on 1 June 1355, which included the release of all prisoners, the compensation of losses, and the submission of all disputes and damages claimed by each side since 1299 to arbitration. Furthermore, both sides agreed to refrain from trading with Tanais for three years—effectively forcing the Venetians to trade via Genoese Caffa. A deadline of 60 days was stipulated for ratification, with a sum of 100,000 gold florins deposited as guarantee. As the historian Steven Epstein commented, "Basically, the treaty restored peace and established mechanisms for settling future disputes; neither side won anything worthy of mention". ==Aftermath==