 Complete the following phrase:  Kefallonia and Zakynthos became the County palatine of Cephalonia and Zakynthos until 1357, when this entity was merged with Lefkada and Ithaki to become the Duchy of Leucadia under French and Italian dukes. Corfu, Paxi and Kythera were taken by the Venetians in 1204, after the dissolution of the Byzantine Empire by the 