He was not "Greek". Corfu was not Greece before the second world war.
His name is not 100% certain, he was either from Istria with the rank of "Capo" = Captain) (Capo d"Istria = Captain of Istria) or had the Italian surname Capodistria (not related to the Capo's d"Itria).
His name was probably "Capodistria" because he was Count Capodistria and not Cound Captain d"Istria.
The truth must be found and told.