The top three Argollëan noble titles are Rí (King), Rí-ruirech (King of Overkings) and Ard-rí (High King). What happened to Ruiri (Overking)? This peeves me much, much, more than it should, but it just seems really weird to have Rí-ruirech without Ruiri.
Obviously, the title of Overking was retired, after some legendary historical Overking managed a great feat of heroics >.>
maybe Overking is like Archduke, and only a scant few get the title.
Or, much like “rex” for the Romans, some particularly bad overking ruined it for everyone.