The Crusaders' Conquest of the Peloponnesus — Monemvasia under the Franks (1248 — 1263)

At the instigation of the Venetian doge, the west European knights of the Fourth Crusade conquered Constantinople, and plundered the Byzantine empire, instead of contesting the Turkish occupation of Jerusalem. The arrival of the crusaders, the so called "Franks," brought an era of still greater importance for Monemvasia. The crusaders quickly took possession of nearly all of Greece, conquering cities and fortresses, and founding principalities that, in some cases, lasted more than five centuries. For example, they established the Latin Empire of the East, the Kingdom of Thessalonica, the Duchy of Athens, as well as other principalities and duchies on the Ionian and Aegean Islands. On the Peloponnesus, known throughout the Middle Ages and into the nineteenth century as "Morea," the French knight Geoffroy de Villehardouin, from the region of Champagne, set up the Principality of Achaia and Morea. For its part in the Fourth Crusade, Venice received three eights of the conquered Byzantine Empire, choosing islands in particular, so as to establish a string of bases for its maritime routes through the Mediterranean. Only a few of the former Byzantine territories remained in Greek control. These included the Despotate of Epirus (in the northwest part of modern Greece), and the cities of Corinth, Nauplia, Argos, and Monemvasia.

After the loss of Constantinople, the Byzantine Greeks in Asia Minor began to consolidate their power, and to attempt to reconquer the lost European parts of the Byzantine Empire. Those cities that the Franks had not conquered played an important role in these attempts, for they were coastal cities, and therefore had ready access to the imperial court, which had taken up residence at Nicaea in Asia Minor. Unlike the new rulers of the Morea, these commercial cities had their own fleet of ships, with which they could provide weapons and fresh supplies for rebels in the Frankish principalities. Thus, Geoffroy de Villehardouin, and his successors Geoffroy II and Guillaume, devoted much effort to trying to gain control of these last Greek footholds on the Morea. The Franks conquered Corinth and Argos, and convinced Nauplia to surrender. Apparently, the Greek populace considered Frankish taxation less oppressive than that of the Byzantine emperors. Monemvasia, however, refused to surrender. The Franks besieged the rock from the mainland, and attempted to take it by direct assaults. All of this, however, proved unsuccessful in the face of the unassailable fortifications, the residents' will to hold out, and the support and resupply that the defenders received by sea from the Nicaean Greeks.

The west European conquerors had introduced feudalism into Greece. Guillaume could thus strengthen his own forces by calling up a feudal levy of Frankish knights. He got further reinforcements from Venice, the greatest naval power in the Mediterranean. In siding with Guillaume, Venice was serving its own self interest. In return for the loan of four fully manned and equipped war ships, Guillaume ceded to Venice the fortified seaports of Modon and Coron (Methone and Korone), two important strongholds in the eastern Mediteranean. This military enterprise also afforded Venice the opportunity of eliminating one of its strong competitors in the Levantine trade, and of gaining compensation for the losses which the pirates of Monemvasia had dealt to Venetian ships.

In 1246 Guillaume began a three year blocade of Monemvasia, which, at first, was unsuccessful. The Venetian ships could indeed block the provisioning of the city by sea, but the residents of Monemvasia had laid in a reserve of supplies. Guillaume's war machine caused much damage, but it could not break the will of the populace to defend itself. Only during the third year of the blocade, when the stock of provisions was used up, the local residents were reduced to eating dogs and cats, and relief was still not in sight, did the city declare itself ready to surrender. But even in these dire straits, the residents did not loose their sense of pride. They had succumbed, but they were not defeated. This attitude is evident in the fact that the archons presented the Franks with conditions for surrender. They insisted that the residents of Monemvasia be allowed to keep their property, remain tax exempt, retain their special privileges, be free of feudal military service, and otherwise be accorded the same rights as the Franks. They agreed to place their ships at the disposal of the Franks, but only under the same conditions as had applied to the Byzantine emperors; that is, the Franks had to pay a considerable fee. Guillaume de Villehardouin was wise enough to accept all these conditions, and thus he continued Byzantine tradition regarding Monemvasia: He not only confirmed the city's privileges, he even extended them.
In 1249 the actual surrender took place; the Franks allowed the residents and their officials to emigrate; the Byzantine Emperor offered them the city of Pegai on the Propontis as a new home. From the time of the surrender, the Frankish princes could call themselves lords of the entire Morea. For the Byzantine emperor at Nicaea, the loss of Monemvasia was a serious blow to his plans for reconquering Greece. For Monemvasia itself, the fall to the Franks meant a further increase in the city's importance. Monemvasia actually expanded its estates on the mainland. It also became the seat of a Roman Catholic bishop, who took up residence along side the Greek Orthodox metropolitan in the city.

However, Monemvasia did not remain for long in the possession of the Princes of Achaia and Morea. Guillaume de Villehardouin, together with his allies, launched a campaign against the Byzantine Emperor, Michael VIII Palaeologus. The latter had himself reconquered Constantinople, thereby ending the brief episode of the "Latin Empire." Guillaume's expedition ended in his own defeat and capture in 1260. After three years' imprisonment, he agreed to cede to the Byzantine empire the cities and fortresses of Maina, Mistra, and Monemvasia, in return for his own freedom. Thus the Frankish dominion over Monemvasia lasted for only fourteen years, and left no traces that are still evident today.