He succeeded his father, Geoffrey Chauderon, Baron of Estamira and Grand Constable of Achaea, in 1278.
[2] He also received lands in Italy from King Charles, who entrusted him with important diplomatic missions.
[3] In 1278, as Prince William of Villehardouin lay dying, he designated John as his bailli, until King Charles of Anjou could make his own arrangements.
The embassy succeeded in obtaining only a verbal promise, and that thanks to the intercession of the Angevin ambassador to Constantinople, but the emperor also sent orders to his local governor to refuse to hand the castle over.
In the event, Kalamata was surrendered to the Achaeans due to the intervention of a local Greek magnate.