William I de la Roche

William I de la Roche (died 1287) succeeded his brother, John I, as Duke of Athens in 1280. He was the first official "duke" of Athens; previous dukes had actually been "lords."

William reversed the territorial losses of his brother's reign, extending his control over Lamia and Gardiki as far as Argos and Nauplia. He married Helena Angelina Comnena, daughter of John Angelus Comnenus, Duke of Neopatria, securing a military alliance with him.

In 1285, while Charles II of Naples, nominal prince of Achaea, was imprisoned, Robert of Artois, regent of the kingdom, named William bailiff and vicar-general of Achaea. He built the castle of Dimatra to defend Messenia from the Byzantine Empire. He was then the most powerful baron in Frankish Greece. In 1286, he arbitrated the succession of the March of Bodonitsa following the death of Isabella Pallavicini. He chose her cousin Thomas over her widower Antoine le Flamenc.

William's rule was peaceful, but short, as he died two years after assuming power in Achaea. He was succeeded by his minor son Guy.

References

*Setton, Kenneth M. (general editor) "A History of the Crusades: Volume II — The Later Crusades, 1189 – 1311". Robert Lee Wolff and Harry W. Hazard, editors. University of Wisconsin Press: Milwaukee, 1969.