this: the branch represented by theEmpress Mary of Constantinople,
along with her husband, Baldwin II.
Charles’s victory had made him the heir to the traditional interests of
the Sicilian kings in the waters surrounding their realm and, especially,
in the fate of the northern Balkans and Greece. Indeed, Charles had
obtained a claim to a string of territories directly opposite his new
kingdom, along the coast from Durazzo down to Corfu.^97 Charles
clearly identified this region as the base from which he might be able
to assert himself against the resurgent Byzantine empire (that is, against
the Nicaeans, who had recaptured Constantinople less than a decade
earlier). As a result, beleaguered French lords, with land or claims in
the Latin empire, were not slow to identify the new king of Sicily as their
potential saviour. Even the most powerfulfigure in Frankish Greece,
William of Villehardouin, prince of Achaia, hastened across the Adriatic
to negotiate with Charles in person. Moreover, it is not surprising that
William encountered his suzerain there, Baldwin II.^98 As we have seen,
the Latin imperial couple had long wished that their succour would
come from southern Italy. After Charles’s conquest, these hopes
redoubled. Not only was the new king of Sicily their close kinsman
but, unlike his predecessor, he was alsopersona gratato the pope.
A series of deals were hammered out at Viterbo, in the late spring of
1267, which did much to shape the future of Frankish Greece. On
18 May, it was agreed that Philip of Courtenay, Baldwin and Mary’s
son and heir, would marry Charles’s daughter Beatrice. Less than
a week after that, a treaty was made between the king of Sicily and
William of Villehardouin. In exchange for protection and support, the
prince formally ceded Achaia to Charles on the understanding that
William would continue to hold it for life. On his death, though, the
principality would pass to his daughter Isabella, who would wed one of
Charles’s sons and, if there was no heir of this marriage, Achaia would
revert to the Sicilian crown. Three days later, on 27 May, there came a
final agreement, between Baldwin and Charles, that completed the
proceedings. Charles promised that within six or seven years, he would
provide 2,000 cavalry for a year’s service to recover Constantinople.
In return, Baldwin confirmed Angevin suzerainty over all the Greek
territories that remained in Latin hands–including, of course, the
principality of Achaia. He also recognized Charles’s right to the land
that the latter claimed along the Epirote coast, and conceded a third
(^97) The classic account of all this can be found in Longnon,L’empire latin de Constantinople et
98 la principautée de Morée, 234–5. See also Chrissis,Crusading in Frankish Greece, 201–4.
Longnon,L’empire latin de Constantinople et la principautée de Morée, 236.
122 The Angevins and Athens (c. 1267–1311)