Anna Komnene Doukaina (died 4 January 1286), known in French as Agnes, was princess-consort of the Principality of Achaea in 1258–1278 and regent between 1259–1262, during the captivity of her husband, Prince William II of Villehardouin, by the Byzantine emperor Michael VIII Palaiologos.
These marriages were part of a web of alliances directed against the Empire of Nicaea, whose expansion threatened both the interests of the Epirote ruler, who claimed the Byzantine imperial heritage for himself, and the very existence of the Latin states of Greece.
[2][3] Prince William and most of his barons were captured at the battle,[4] and until their return, Anna governed the Principality of Achaea in her husband's name, with the assistance of the Duke of Athens, Guy I de la Roche.
She also became guardian of her youngest daughter Margaret, while Isabella had been married to Charles' son Philip and had gone to Italy, where she remained even after her husband died in 1277.
This worried King Charles, who was uneasy to see Chlemoutsi, the strongest castle in Achaea, and Kalamata, which comprised some of the Principality's most fertile lands, in the hands of an already powerful vassal.