a ruler who has absolute power
Baron Longlight has become an autarch, with no advisors and no one to question his authority in these lands.
This one took a bit, the first dictonary I tried only had autarchy, so googling found the definition above. A little more digging found that the difference between this word and dictator is that dictator wasn’t always an absolute ruler. It was originally “a magistrate without colleague in republican ancient Rome, who held full executive authority for a term granted by the senate (legislature), typically to conduct a war.” -WikiDiff Autarch has always meant a despotic ruler.
This makes this another one of those words that’s good for aging or shifting the dialect of an NPC. If your running a Rome or Greek era earth game, then there’s a difference.