Treason alert: this list intentionally omits some of history’s most infamous traitors, because a search for “history’s most infamous traitors” delivers page after page of pretty much the same list. Apparently some writers are traitors against originality.So while we absolutely had to include the man synonymous with treason, Benedict Arnold – who singlehandedly almost killed America in its cradle – the remainder of this chronological collection includes lesser-known, yet no less treacherous, turncoats.