The Ottoman Empire in the 17th century is a land of many contrasts. I know that sounds like the opening to a bad high school essay, but it’s not wrong. The 17th century ended with the Ottomans signing the first disadvantageous treaty they’d ever signed, and while reports of Ottoman decline in this period are greatly exaggerated, I think it’s fair to say that this was a sign of relative, if not absolute, Ottoman decline. In other words, their enemies were catching up to them. On the other hand, the mid-century (1645-1669) Cretan War, or the Fifth Ottoman-Venetian War if you prefer, brought the empire to its largest territorial extent. Sure, that includes places like Algiers and parts of Arabia where the empire had little real authority, but oh well. The siege we’re talking about today was the centerpiece of that war and, as it so happens, one of the longest sieges in recorded history at a whopping 21 years and almost five months.
The Cretan War was fought over, yes, that’s right, Crete. The island had been, as the Kingdom of Candia, part of Venice’s maritime empire since 1205, after Fourth Crusade leader Boniface of Montferrat sold the Byzantine Empire’s claim on it to Venice. Granted, the Byzantine Empire’s claim to Crete wasn’t exactly Boniface’s to sell, but it’s no use crying over spilt milk, right? The point is that from then on Venice controlled the island, and the 17th century Ottomans coveted it. It was the next big Mediterranean island moving west from Cyprus, which the Ottomans had captured from Venice in 1571, and it also happened to be Venice’s last big island possession, so for both of those reasons it was the natural next target in the empire’s Mediterranean plans.
The Ottomans and Venetians were at peace, and had been since the Fourth Ottoman-Venetian War (the one that included the Battle of Lepanto) ended in 1573. But in 1644, the Knights of Malta attacked an Ottoman fleet in the eastern Mediterranean that was carrying a few high Ottoman officials and a number of people making pilgrimage to Mecca. The officials were mostly killed and many of the passengers were taken as slaves. The pirates (or privateers, I guess) made for Crete, and depending on which side’s version of events you believe they either stayed there for several weeks and bestowed part of their loot upon the Venetian governor or they had barely landed–without permission–before the Venetian authorities forced them to be on their way. Obviously either story can be seen as self-serving, but clearly the Ottomans believed the former and weren’t about to be persuaded otherwise. Either way, the Venetians seem to have been caught off guard when a punitive, ~50,000 man strong Ottoman invasion force arrived at Crete in late June, 1645, rather than continuing on to Malta.
The Venetians had several problems. One, they were vastly outnumbered and couldn’t possibly hope to defend the island with a force comparable to the one the Ottomans brought ashore–Venice was not a large state, and the devastation caused by the Thirty Years’ War, which wouldn’t end until 1648, meant that the rest of Europe was unable to offer much assistance. Two, they weren’t especially popular among the Greek Cretans, and this is ultimately why the Ottomans were able to sustain a 21+ year long siege on an island in the middle of the Mediterranean at a time when, as we’ll see, the Ottomans had little ability to send new supplies by sea. They easily controlled the countryside surrounding the major Venetian cities, and the locals kept them well-supplied, so they didn’t have to worry about feeding themselves. An outbreak of plague in the winter of 1646-1647–which we’ll come back to at the end of this piece–hit everybody on Crete hard but appears to have made it easier for the Ottomans to consolidate control over the rest of the island and prepare to besiege the capital, Candia (modern Heraklion). Which they did, starting in May 1648.
The Ottomans tried but repeatedly failed to break down Candia’s walls, so instead they tried to choke the city off from its water supply, on land, and from Venice, at sea. The Venetians couldn’t counterattack the Ottomans on land, but they were still a major naval power, and so they attempted to block up the Dardanelles to prevent the Ottoman fleet from resupplying their forces. This tactic worked very effectively for several years–a series of naval engagements in the mid 1650s went Venice’s way, meaning they could keep the straits blocked to Ottoman traffic. This not only affected the army on Crete, which couldn’t do much beyond sitting there and surrounding Candia without reinforcements, but also began to adversely affect life in Constantinople. The 1656 appointment of a new Grand Vizier, Köprülü Mehmed Pasha (d. 1661), turned this situation around. Köprülü enlarged the Ottoman fleet considerably, and this was enough to drive the Venetians from the Dardanelles by the end of 1657.
Candia continued to hold out, in part because Ottoman attention was elsewhere. But the conclusion of the Peace of Vasvár in 1664, ending the 1663-1664 Ottoman-Habsburg War, hastened the city’s fall by allowing the Ottomans to shift more resources to Crete. A new army, under Köprülü’s direct command, arrived on the island in late 1666, but even at this the siege took over two more years to conclude, at the cost of tens of thousands more lives–mostly among the Ottomans, who lost far more men overall during the course of the siege than did the Venetian defenders. But the Ottomans simply refused to lift the siege, and Candia was losing its ability to hold out. The defeat of a French relief force in mid-summer was the last straw for the defenders, who had fewer than 5000 men in fighting condition left at their disposal, and so they surrendered in exchange for safe passage off the island and continued Venetian possession of several smaller islands near Crete and in the Aegean, where Venetian ships could stop on their way east.
While all this was going on, the Venetians were actually winning on the war’s second front, in Dalmatia (part of modern Croatia). The Ottomans were at a logistical disadvantage trying to defend this territory, which was so hard to get to from Constantinople but so easily accessible from Venice. Anyway, Crete was the prize, and the Ottomans were happy to trade territory in Dalmatia for it, which is how the two sides ended the war. Crete remained part of the Ottoman Empire until 1897, when an uprising (one of a number of 19th century uprisings on the island, whose people wanted to be part of the newly independent Greece) caused the intervention of the European powers and the creation of an independent Cretan state under Ottoman jurisdiction. Crete finally declared its union with Greece in 1908, but that union wasn’t formally recognized until 1913, as part of the Ottoman defeat in the First Balkan War.
I said I’d come back to the plague at the end of this piece, and the reason is that, fairly recently, research in the Venetian archives has uncovered evidence of a plan, never implemented, for the defenders of Candia to employ biological warfare against the Ottomans. The plan called for a liquid to be made from the spleens and buboes (I know, sorry) of dead plague victims that would then be used against Ottoman camps all over the island. It’s unlikely that this plan would’ve succeeded–the plague bacteria probably wouldn’t have survived long enough–but the Venetians had no reason to know that, and it’s not clear why they wound up nixing the plan. Germ warfare and the bubonic plague have a long history together–it’s believed, for example, that the Mongols catapulted plague-riddled corpses into the Crimean city of Kaffa (modern Feodosia) in the mid-1340s while they were besieging that city. For a long time it was believed that this incident led to the Black Death, but modern research suggests that the plague’s transmission from Crimea to the rest of Europe probably happened independently of the siege.