Benjamin first appears in 1297, when, following the death of the Prince of Achaea, Florent of Hainaut, his widow, Princess Isabella of Villehardouin withdrew to the castle of Kalamata.
To govern the Principality, Isabella appointed Richard Orsini to rule in her stead as bailli and named Benjamin, who had been the protovestiarios of the Principality—an office equivalent to a Western chamberlain and charged with keeping the list of fief-holders[1]—as the new chancellor.
The new Prince quickly made himself unpopular in Achaea by his arrogance, despotic manners, and disregard for the principality's feudal customs.
[4] Immediately after his arrival, acting on the advice of a partisan of Richard Orsini, Philip arrested Benjamin on charge of treason and imprisoned him at Andravida.
Nicholas of Saint Omer immediately confronted the new prince at Glarentza and vehemently protested this act; violence was averted through the intervention of Isabella and Philip's counsellors.