STS Bulletin no.13
Oligarch, a successful Russian thief. A successful British thief is an entrepreneur. Richard Branson is not an oligarch because he is not Russian.
The oligarchs of Russia were originally referred to in their homeland as the kleptocracy, another Greek word and a favourite of mine. No British media outlet would use this word (British libel law) so oligarch is the acceptable label.
"Behind every great fortune there lies a crime." (Honoré de Balzac, "Il y a un crime caché à l’origine de chaque grande fortune.")