Initially, Arcadia—the medieval name of Kyparissia on the western coast of Messenia—formed part of the princely domain of the Villehardouin family.

Erard disappears after 1279, when he was captured by the Byzantines, but Geoffrey did not manage to reclaim his brother's portion until 1293, due to the obstructions of the Angevin baillis, who sequestered the domain.

[5] Erard II died some time before 1338, but Peter dalle Carceri, Triarch of Negroponte, is already attested as lord of half the barony in 1324, and it is usually assumed that Erard II left his half of the barony to his widow, Balzana Gozzadini, who took Peter as a second husband.

[6] Agnes married in 1324 Stephen Le Maure ("The Moor"), Lord of Saint-Sauveur and Aetos, and had a son, Erard III, who by 1344 managed to reunite the barony, and was named marshal of Achaea in 1345.

After the conquest of Patras and Chalandritsa by the Byzantines of the Despotate of the Morea in 1429–30, which signalled the de facto end of the Principality, the last Prince, Centurione II Zaccaria, retained Arcadia as his personal fief, but after his death in 1432, his son-in-law, Despot Thomas Palaiologos, annexed it and imprisoned Centurione's widow, who died in prison.