Siege of Thessalonica (1422–1430)

 

The siege of Thessalonica between 1422 and 1430 saw the

Thessalonica had already been under Ottoman control from 1387 to 1403 before returning to Byzantine rule in the aftermath of the Battle of Ankara. In 1422, after the Byzantines supported Mustafa Çelebi as a rival pretender against him, Murad attacked Thessalonica. Unable to provide manpower or resources for the city's defence, its ruler, Andronikos Palaiologos, handed it over to the Republic of Venice in September 1423. The Venetians attempted to persuade the Sultan to recognise their possession, but failed as Murad considered the city his by right and the Venetians to be interlopers. This impasse led to an Ottoman blockade of Thessalonica, which occasionally flared up with direct attacks on the city. At the same time, the conflict was mostly fought as a series of raids by both sides against the other's territories in the Balkans and the Aegean Islands. The Venetians repeatedly tried to apply pressure by blocking the passage of the Dardanelles at Gallipoli, with little success.

The blockade quickly reduced the inhabitants to near starvation, and led many to flee the city. The restrictions placed on them by the siege, the inability of Venice to properly supply and guard the city, the violations of their customary rights, and rampant profiteering by Venetian officials led to the formation of a pro-surrender party within the city, which gained strength among the inhabitants. The city's metropolitan bishop, Symeon, encouraged his flock to resist. However, by 1426, with Venice's inability to secure peace on its own terms evident, a majority of the local population had come to prefer a surrender to avoid the pillage that would accompany a forcible conquest. Venice's efforts to find allies against the Ottomans also failed: the other regional potentates either pursued their own course, were themselves antagonistic to the Venetians, or were defeated by the Ottomans.

After years of inconclusive exchanges, the two sides prepared for a final confrontation in 1429. In March, Venice formally declared war on the Ottomans, but even then the conservative mercantile aristocracy running the Republic were uninterested in raising an army sufficient to protect Thessalonica, let alone to force the Sultan to seek terms. In early 1430, Murad was able to concentrate his forces against Thessalonica, taking it by storm on 29 March 1430. The privations of the siege and the subsequent sack reduced the city to a shadow of its former self, from perhaps as many as 40,000 inhabitants to c. 2,000, and necessitated large-scale resettlement in the following years. Venice concluded a peace treaty with the Sultan in July, recognising the new status quo. Over the next few decades, the antagonism between Venice and the Ottomans morphed into a rivalry over control of Albania.

Background

In the 14th century, the nascent

Initially the surrendered cities were allowed complete autonomy in exchange for payment of the haraç poll tax. Following the death of Emperor John V Palaiologos in 1391, however, Manuel II escaped Ottoman custody and went to Constantinople, where he was crowned emperor, succeeding his father. This angered Sultan Bayezid I, who laid waste to the remaining Byzantine territories, and then turned on Chrysopolis, which was captured by storm and largely destroyed.^[4] Thessalonica submitted again to Ottoman rule at this time, possibly after a brief period of resistance,^[a] but was treated more leniently: although the city was brought under full Ottoman control, the Christian population and the Church retained most of their possessions, and the city retained its institutions.^[8][9]

Thessalonica remained in Ottoman hands until 1403, when Emperor Manuel II sided with Bayezid's eldest son

The eventual victor in the Ottoman civil war, Mehmed I (r. 1413–1421), maintained good relations with the Byzantines who had supported him.^[b] The accession of Murad II (r. 1422–1451) changed the situation, as John VIII Palaiologos (r. 1425–1448), the heir-apparent and de facto regent for the ailing Manuel II, set up Mustafa Çelebi as a rival to Murad. After defeating his opponent, Murad, determined to extinguish the remnants of the Byzantine state, laid siege, unsuccessfully, to Constantinople from 10 June to 6 September 1422.^[19][20] In June 1422, Burak Bey, the son of Evrenos, assisted by various Ottoman marcher-lords of the Balkans, besieged Thessalonica as well, and ravaged its suburbs and the western portion of Chalcidice.^[21][22]

According to the city's metropolitan bishop, Symeon (in office 1416/17–1429), both he and Despot Andronikos sent repeated pleas for aid to Constantinople, but the imperial government was short of resources and preoccupied with its own problems. Eventually, a single unnamed commander was sent to the city, but he brought neither men nor money with him. This commander proposed setting up a common fund of the citizens to support the defence, but this proposal met with vehement opposition, particularly from the wealthy aristocrats, who would naturally have borne the brunt of the cost. The common people likewise proved unwilling to contribute; when the news spread that the Ottomans had offered a peaceful settlement, provided that Despot Andronikos left the city, the commoners even rioted in favour of an accommodation with the Ottomans.^[23]

At that point a group of aristocrats persuaded the Despot to seek the assistance of the

The offer arrived in Venice at an opportune time. The election of Francesco Foscari on 15 April 1423 as Doge of Venice had placed a proponent of a more aggressive and unyielding stance against Ottoman expansionism at the head of the Republic.^[31][32] But the majority of the Great Council of Venice was still dominated by the more cautious tendencies of the merchant nobility that ruled the Republic and they feared the disruption to trade that open war with the Ottomans would bring.^[31] Since the Fourth Crusade, the Venetians had consciously adopted a policy of gradually acquiring outposts, fortresses and islands from the collapsing Byzantine Empire, providing bases that secured Venice's valuable trading links with the East.^[33] For some time Venice had viewed Thessalonica as a possible expansion target, especially as Constantinople seemed to be on the verge of falling to the Turks. Thus in 1419, Venice re-established a consulate in the city, headed by a local Greek, George Philomati, and after his death in 1422 by his brother Demetrios.^[34]

At a session of the Great Council on 7 July, Andronikos' offer was accepted. The council sent notices to the Venetian colonies in the

Nevertheless, large segments of the population continued to support the seeking of a settlement with the Ottomans; the writings of Metropolitan Symeon record that a number of inhabitants fled at this time to the Ottomans.[40] This sentiment even included some members of the nobility: the contemporary Byzantine historian Doukas records that soon after taking over the city, the Venetians imprisoned four leading aristocrats, led by a certain Platyskalites, for their association with the Ottomans. The four men were exiled, first to Crete, and then to Venice itself and finally to Padua. Only after the fall of Thessalonica in 1430 were the two survivors released.^[41] The contemporary Venetian Morosini Codex records a story of a conspiracy – dismissed as "slanderous" by Donald Nicol^[42] – led by Despot Andronikos to hand over the city to the Turks. The plot was reportedly discovered in November 1423, and Andronikos and his supporters were exiled, with the Despot sent to Nauplia.^[d][45]

Diplomatic and military events during the siege

Initial Venetian and Ottoman diplomatic and military approaches

The Venetians hoped to secure Ottoman consent to the occupation of Thessalonica. However, when the provveditore Giorgio attempted to carry out his mission to the Sultan's court, probably in February 1424, he was unsuccessful to the point of being arrested and imprisoned by Murad.^[30][46] The Ottomans refused to accept the handover, considering the Venetian presence illegal on account of their previous right to the city through conquest.^[47] The Ottoman attitude was summed up by the reply allegedly given by Murad to Venetian ambassadors seeking peace, as recorded by Doukas:

This city is my paternal property. My grandfather Bayazid, by the might of his hand, wrested her from the

Romans [the Byzantines]. Had the Romans prevailed over me, they would have cause to exclaim, 'He is unjust!' But you are Latins from Italy, why have you trespassed into these parts? You have the choice of withdrawing. If you do not, I will come posthaste.

— Sultan Murad II to the Venetian envoys, Doukas, Historia Turco-Byzantina XXIX.5^[22]

When news of Giorgio's arrest arrived in Venice, the Great Council decided to replace both him and Venier. The first two choices for replacement, Jacopo Trevisan and Fantino Michiel, refused, but in May 1424, Bernardo Loredan was named duke (governor) of the city, with Jacopo Dandolo as captain (military commander), for a two-year term.^[48] In the meantime, Venier was instructed to secure the release of Giorgio, and recognition from the Sultan of Venetian control over Thessalonica, the surrounding villages, and the fort of Kortiach (Mount Chortiatis). In exchange, he was to offer an annual tribute of 1,000 to 2,000 ducats, and to distribute annuities to the Sultan's chief courtiers. The same instructions were given to the new captain-general of the fleet, Pietro Loredan, who sailed for Thessalonica. If he found the city under siege, Loredan was to attack Gallipoli (where he had scored a major victory in 1416^[49]), hinder the passage of Ottoman troops over the Dardanelles, and if practicable, to try and stir up opposition to the Sultan among neighbouring rulers. To emphasise the fact that Venice did not desire war, Loredan was instructed to inform the local Turkish commanders that his actions were only as a consequence of the imprisonment of Giorgio and the siege of Thessalonica, which they had acquired legally.^[48][46]

This set the pattern for the six-year conflict between the Ottomans and Venice over control of Thessalonica. While the Ottomans blockaded and attacked Thessalonica from land, trying to starve it into surrender, the Republic sent repeated embassies to secure recognition of her possession of Thessalonica in exchange for an annual tribute. To back up their diplomatic efforts, the Venetians tried to put pressure on the Sultan by stirring up trouble along the Ottomans' periphery, sponsoring efforts for an anti-Ottoman

In July 1425, ten Venetian galleys under Michiel undertook an expedition east along the shores of Macedonia: the Venetians found Ierissos abandoned by its Ottoman garrison, but full of provisions, which they loaded onto their ships. After setting fire to the town and five other forts in the vicinity, the fleet moved onto Christopolis. The Venetians found the castle held by a 400-strong force of Ottoman sipahis, under the command of Ismail Bey. The first attempt to land, led by Alvise Loredan, was repulsed, and only after all the ships mustered their forces were the Venetians able to overcome Ottoman resistance in a four-hour-long battle: 41 Turks were killed, including Ismail Bey, and 30 taken prisoner. After strengthening the site with a stone wall and earthworks, and leaving a garrison of 80 foot soldiers and 50 crossbowmen to hold it, the fleet departed. The Turks soon returned with a larger force of 10,000–12,000 men, and after about twenty days, and despite losing around 800 men, the Ottomans stormed the castle. Unable to escape, half the Venetians were killed and the rest taken prisoner.^[56][57]

On 21 July Manuel II died, and John VIII formally became Emperor. In response Murad, who was deeply hostile towards John, launched his forces on raids around Thessalonica and Zetouni (

In April 1426, Michiel came near to a settlement with the Ottoman governor at Gallipoli, whereby the Republic would keep Thessalonica in exchange for 100,000 aspers a year, the right of disputes between Turks in the city to be settled by their own kadi, and free and untaxed movement of merchants to and from the city. The negotiations foundered again, however, as the Ottomans insisted on their control of Kassandra and Chortiatis, which they intended as springboards for the eventual conquest of the city.^[64] At the same time, the Ottomans launched a major attack on the city with reportedly 30,000 men, but the presence of five Venetian galleys in the city, possibly armed with small cannons, helped the defenders repel the attack. According to the report of Loredan and Dandolo to the Great Council, 700 crossbowmen manned the walls, and over 2,000 Turks were killed before the assault failed.^[65][66]

On 6 May, a new duke and captain for the city were elected: Paolo Trevisan and Paolo Orio.^[67] In July 1426, the new Venetian captain-general, Andrea Mocenigo, was instructed to resume negotiations, but concede to the Ottomans possession of Kassandra and Chortiatis. On the other hand, the peace settlement should be comprehensive, including the Latin lords of the Aegean, who were Venetian citizens and clients. Failing that, Mocenigo was to attack Gallipoli.^[68] In August, the Despot of Serbia, Stefan Lazarević, offered his services as mediator.^[69] On 28 November, Mocenigo managed to receive Murad's agreement to a peace treaty on the broad lines of the agreement proposed by Michiel, except that Venice would pay an annual tribute of 150,000 aspers and increased annuities for senior members of the Ottoman court, and would surrender Chortiatis.^[70] Despite the Republic's desire to conclude a peace treaty, the months and years dragged on without an agreement. Benedetto Emo, appointed ambassador to the Sultan in July 1427 with the express purpose of ratifying the treaty, was replaced in August 1428 by Jacopo Dandolo. Dandolo was instructed, if necessary, to offer a further increase of the tribute to 300,000 aspers, and a total sum of gifts from 10,000–15,000 ducats and a further 2,000 ducats as annuities; further sums could be offered in exchange for possession of the environs of Thessalonica, Kassandra, and the salt works. Dandolo did not have any more success than his predecessor: the Sultan demanded of him the surrender of Thessalonica, and when Dandolo replied that he did not have authority to do this, the Sultan had him thrown in prison, where he was left to die.^[71][72]

Diplomatic and military events, 1428–1429

Throughout the confrontation over Thessalonica, the Ottomans launched constant raids against Venetian possessions in Albania.

According to the Venetian senator Andrea Suriano, Venice spent on average 60,000 ducats per year in this seemingly fruitless conflict, but the Venetians themselves were hesitant to commit their resources fully to Thessalonica; its proximity to the centre of Ottoman power made their ability to retain it doubtful in the long term, while at the same time, closer to home, Venice was pursuing a conflict with the Duchy of Milan over control of northern Italy.^[77][78] The Republic had long tried to avoid declaring war on the Ottomans, but now it had little choice: Dandolo's imprisonment, the increasing Ottoman naval threat (with the open assistance of the Genoese colonies at Chios and Lesbos), in conjunction with the end of their war with Hungary, made clear to the Venetians that the Sultan was preparing to settle the question of Thessalonica by force. As a result, on 29 March 1429, the Great Council voted an official declaration of war against the Sultan, and ordered more ships to be activated to join the fleet.^[76][78][79]

On 11 May, the pretender Mustafa appeared before the Great Council, and was given a gift of 150 ducats for his services.^[65] On 4 June a new duke and captain were elected for Thessalonica, Paolo Contarini and Andrea Donato, after the first three pairs chosen all declined the post, despite the fine attached to refusal; a clear indication of the unwillingness of the Venetian nobles to undertake this unprofitable and perilous task.^[80][81] On 1 July, Mocenigo attacked the Ottoman ships at Gallipoli, but although he led his flagship to break through the palisade protecting the Ottoman anchorage, the other Venetian vessels did not follow, forcing Mocenigo to withdraw with heavy casualties.^[82][83] Even at this point, Venice would not commit its full force to the conflict: when Suriano, as a proponent of the hawkish faction, proposed to arm a fleet of 14 ships and engage in a more decisive policy against the Ottomans in January 1430, the proposal was voted down, even though it was rather modest and clearly inadequate to force the Sultan to come to terms.^[84] Instead, the Great Council instructed the new captain-general, Silvestro Morosini, to seek the mediation of the Byzantine Emperor for a settlement on the lines of the previous agreements.^[85]

Aware of their own weakness, the Venetians tried to form alliances with other regional rulers who feared Ottoman expansionism. Taking advantage of the Ottomans' preoccupation with the Siege of Golubac,

Inside Thessalonica, the siege led to much suffering, and the populace quickly became dissatisfied with their new masters. By the winter of 1426–1427, conditions in the besieged city approached the point of famine. The Thessalonians were forced to subsist on bread alone, and even that proved problematic: The authorities were forced to request more shipments of wheat from Venice when supplies ran dangerously low. The conditions of "extreme poverty, death, and destitution" made the Greek population more and more restless, and even those who had formerly welcomed the Venetians began to waver.^[79][88] The lack of food even jeopardised the city's defences, since many of the mercenary guards on the walls, paid by Venice with wheat instead of cash, defected to the Turks when their rations were late. This situation became progressively worse, and by the time of the final Ottoman attack in 1430, many soldiers had no weapons because they had sold them for food.^[89]

The privations of the siege led to an exodus of the city's population, as citizens with the ability to leave sold their possessions and fled to Constantinople, other Venetian-controlled Greek territories, or to the Turks.^[90] From a population variously reported at 20–25 thousand, or even as many as forty thousand by contemporary Italian sources, it is estimated that only ten to thirteen thousand were left by 1430.^[91] The Venetian authorities tried to put a stop to this by prohibiting the inhabitants from leaving the city, outlawing "all sales, mortgages, and transfers of property, both movable and immovable", and destroying the houses and other property – even trees – of people who had left the city. They hoped that the destruction would serve a deterrent to those who remained behind.^[92] Coupled with several instances of arbitrariness, speculation, and profiteering on behalf of the Venetian authorities, these measures helped to further alienate the Thessalonians.^[93] By April 1425, a Byzantine church official who had had his family flee the city wrote of the "enslavement of the city by the Venetians", and similar sentiments about Venetian tyranny are echoed in all contemporary Byzantine sources.^[94] In their embassy in July 1425, the Thessalonians submitted a list of 21 complaints and demands, including fixed rations of corn for the poor and the lowering of tax dues and suspension of arrears and debt-related punishments for the duration of the siege, since the closing of the gates meant that people could no longer access their fields, which were furthermore devastated by the Turks. In a session on 23 July 1425, the Great Council acceded to many of their demands and requested that its officials respect the customs and rights of the citizens and work together with the local council of twelve nobles in the governance of the city.^[59]

Whatever the Venetian efforts to secure peace, the Thessalonians were well aware, in the words of the Byzantinist

In summer 1429, the Thessalonians sent a second embassy to Venice to complain about the restrictions placed on entry and exit from the city, continued violations of their rights, extortion by the Venetian authorities, the poor supply situation, the neglect of repairing the city's fortifications and the lack of military stores, and the Venetian mercenaries who were in contact with the Turks outside the walls. On 14 July, the Great Council gave mostly reassuring answers to a list of 31 demands, but the increasing dissatisfaction by the Greek population with Venetian rule was evident.[99]^[100][101] The eyewitness John Anagnostes reports that by the winter of 1429, the majority of the population had come to favour a surrender to the Turks. Sultan Murad was aware of the situation inside the walls, and twice sent Christian officers in his service into the city to incite a rebellion against the Venetians. However, as Anagnostes writes, the population was by that time so reduced in number, and divided among itself, that no common cause could be made. Furthermore, the Thessalonians were afraid of the Venetians, as they had recruited a special force of guards, the Tzetarioi, and given them the authority to kill anyone advocating a surrender.^[102]

Fall of the city

A squadron of three galleys under Antonio Diedo arrived to reinforce the city on 17 March 1430, but to little avail. A muster of the city's available defenders showed that they sufficed to man only a half or a third of the

Following long-standing custom for a city taken by storm, the plundering lasted for three days. According to Anagnostes, 7,000 inhabitants,^[i] including himself, were taken captive to be sold in the slave markets of the Balkans and Anatolia,^[117] although many were subsequently ransomed by the Despot of Serbia, Đurađ Branković.^[113] The city's monuments suffered heavy damage in the sack, particularly the cathedral of Hagios Demetrios, as soldiers ransacked them for precious objects and hidden treasure.^[113] This damage was compounded later when the Sultan ordered that marble sections be stripped from them and taken to his capital, Adrianople, to pave a bath.^[118] On the fourth day, Sultan Murad entered the city himself and prayed at the Church of the Acheiropoietos, which became the city's first mosque.^[119] The Sultan then restored order, evicting the soldiers from the homes they had occupied and returning them to their owners.^[113] Only two thousand of the population were left after the sack.^[120] The Sultan soon took measures to repopulate the city. He promised to return their properties to those inhabitants who had fled if they returned, and in some cases even ransomed captives from the sack himself.^[117] In addition, he brought in Muslim and Christian settlers from other areas of Macedonia.^[j] A great number of empty houses were confiscated and given to the settlers, while most of the main churches were converted to mosques. The Turks settled mostly in the upper part of the city, from where they could better control it.^[123]

Aftermath

The Venetians were taken by surprise when the city fell; the fleet under Morosini was still sailing off the western coast of Greece. Following their customary strategy, they reacted by sending their fleet to blockade Gallipoli and cut off passage of the Dardanelles.