We don't have synonyms for despotes yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are despite, despotic and despot.
(n) :
(historical) A title awarded to senior members of the imperial family in the late Byzantine Empire, and claimed by various independent or semi-autonomous rulers in the Balkans (12th to 15th centuries)
(n) :
(historical) A title awarded to senior members of the imperial family in the late Byzantine Empire, and claimed by various independent or semi-autonomous rulers in the Balkans (12th to 15th centuries)