His sworn brother

Detail from icon of Ag. Menas, ca. 1600.

After a battle at Itylo killed 700 Turks,¹ Kladas was pursued further south and was within a couple of days of being captured. But when Kladas arrived at Porto Quaglio/Πορτο-Κάγιον three ships were waiting. Stefano Magno says they had come from Ferdinand II, King of Naples and Apulia -- , to learn Mehmed's intentions towards Apulia, although Mehmed had been besieging Otranto since the previous July -- and on one of the ships was a Zuane Francesco Zanco from Venice, fratello zurado or ἀδελφοποιητὸς of Kladas. Kladas, and many of his followers, escaped.  Minio says, Et scampò el Clada . . ..  

With an extensive use of subjunctives, it is possible to work out a scenario, apparently unmentioned at the time:  Kladas made his effort at revolt under the impression that he would receive extensive aid.

Kladas had been in Venice as recently as September when he received a knighthood from the Doge. It was not only his fourth trip, but he had just spent a whole year in Venice. He turns out to have had this Venetian sworn-brother of whom we have no earlier record, possibly a relationship created and solidified in Venice, although Zanco could well have turned up in Koroni earlier and, given that he was working for the King of Naples, he probably had. Nearly all of Magno's information comes from Koroni sources.

Kladas’ last trip to Venice had been to protest the loss of lands through the peace settlement. When he met Dario and Halil Bey in Koroni, they confirmed to him what was already known, and that the Signoria’s equivocal responses to him had been outright lying. It is a reasonable assumption that when Kladas returned to Koroni after receiving his knighthood, he was planning a revolt.

In this scenario, Francesco Zanco, his sworn brother, in the employ of Naples' Ferdinand II, was an agent-provocateur who encouraged Kladas to think that aid might be forthcoming from Ferdinand who was deeply interested in creating Venetian discomfort, as well as Ottoman. The Kingdom of Naples had taken an intense interest in Byzantine and Moreote affairs for forty years, on more than one occasion offering aid that never materialized -- John was to have a fleet, Constantine was to have troops and settlers in the Morea, Constantine, Thomas, and Theodoros were to have Spanish brides.  There were always tantalizing offers, sympathetic agents. 

In late July of 1480, an Ottoman fleet had attacked and besieged Otranto, raiding as far as Lecce. A few days before the attack, Ferdinand had signed an alliance with Milan, Florence, and Ferrara, against Venice and the Pope, and when he then asked Venice for aid at Otranto, Venice decided that peace with the Ottomans was preferable to rescuing Apulia. So Venetian-Ottoman hostilities offered a hopeful possibility that fall for Naples and Otranto.

Subsequent events do nothing to contradict this. The Apulian ships first offered Kladas aid in the King's name, and then took him off Mani and to Apulia where he was given the title of magnifico from Ferdinand II and a generous allowance. In Apulia he met the Duke of Calabria, a cousin of the late George Castrioti of Albania, and Castrioti's son, John, who were taking advantage of the Ottoman concentration on Otranto to attack Valona. Castrioti was married to Eirene Branković, granddaughter of the Despot Thomas who had been Kladas' overlord until 1460. Another participant was Thomas' son, Andreas Palaiologos, whom Kladas must have met as a child in the Morea twenty years earlier. This effort was a failure, and the Kladas and Kastrioti followers then served the Kingdom of Naples in Italy.

Unless someone can spend time in the Neapolitan archives, that single mention is all we have for the sworn brother.

1The number of 700 is intriguing: during the 15^th century, 700 and 800 turn up continually in reports of Ottoman killings in battle. Eight hundred were beheaded at Tavia in June 1423. Eight hundred were beheaded at Negroponte on 12 July 1471. Eight hundred were beheaded at Otranto on 14 August 1480. Eight hundred were beheaded at Methoni 9 August 1500.