Partitioned into three baronies (terzieri, "thirds") (Chalkis, Karystos and Oreos) run by a few interrelated Lombard families, the island soon fell under the influence of the Republic of Venice.

According to the division of Byzantine territory (the Partitio terrarum imperii Romaniae), Euboea was awarded to Boniface of Montferrat, King of Thessalonica.

Having allied himself with an unsuccessful Lombard rebellion against the Latin Emperor, Henry of Flanders, Ravano was eager to find a powerful protector.

In 1255 however, the death of Carintana dalle Carceri, hexarch of Oreos, led to the so-called "War of the Euboeote Succession", which involved the Principality of Achaea and Venice.

The war ended in the battle of Karydi in May/June 1258, where William defeated the Duke of Athens, Guy I de la Roche, who had allied himself with the rebellious triarchs.

Its successes culminated in the recapture of Constantinople in 1261 and the reestablishment of the Byzantine Empire, whose energetic ruler, Michael VIII Palaeologus, sought to reconquer the remaining Latin principalities in southern Greece.

In 1317 however, Karystos fell to the Catalan Company of Don Alfonso Fadrique, royal vicar-general (governor) of the duchy of Athens and illegitimate son of Frederick III of Sicily.

Note: The sequence of rulers during the 13th century, as well as the familial relations between them, are not very clear, as information about Euboea's internal history is scarce to non-existent, especially for the period 1216–1255.