Funny, it's just the letter "O" in the third century AD. Too bad a couple of Nazis ruined it much later, along with the swastika, which had many innocuous usages before the 20th century.

The word "odal" (estate) for this symbol is cognate with ruler names like Ethel and Attila as well as with allodial titles, for some of its other contexts.

For those who think every circularity with a tail means "Q", it's a bit of a wakeup call. Symbols require context and are not black-and-white. If there were two other symbolic witnesses to the same connection in the same context it would be more significant.

(Digression: the modern redirection by gamers of the OK symbol is an interesting echo of the origin of the phrase "OK" itself. It was invented by political countermovements like the 19th-century American Know-Nothing party, who adopted an early leetspeak in newspapers by deliberately misspelling words and forming abbreviations thereby; you had to have read the right issue of the newspaper to know the running gag. "OK", the most famous of these abbreviations, really does stand for "oll korrect".)