Guy I de la Roche

Buchon and Karl Hopf, supposed that Othon returned to his native Burgundy after 1225, whereupon Guy inherited him in Greece; as J. Longnon pointed out, however, although possible, there is no evidence for it.

The duchy was prospering at the time, however, due to its silk industry (centred at Thebes) and its trade with Venice and Genoa.

When Prince William II of Achaea disputed the suzerainty over the island of Euboea with the Venetians and the local triarchs, Guy supported the latter.

The Chronicle of Morea asserts that Athens, which was technically only a lordship, was officially raised to the status of a duchy only after Guy met with King Louis IX of France sometime in 1260.

In Spring that year, Guy set out to return to Greece, receiving news on the way that William II had been defeated by Emperor Michael VIII Palaeologus at the Battle of Pelagonia and taken prisoner.