For the answer, witness: John Hodgman on the classic comics. Skip past all the crap about "underground" comics and you shall find his origin as a kind of Strongbad character -- a bit part character who slowly took over the Oyl universe:
But with each sock of Bluto’s jaw, the blandly heroic Popeye of today beats down a little further the dim memory of the Popeye born in “Thimble Theatre” in 1929.Emphasis added, obviously. More comics crit like this, please.
At that time, Segar had already been chronicling the Oyl family for 10 years, when the lovable schemer Castor Oyl decided he needed to hire a seaworthy hand for an ocean adventure.
And then, suddenly, there he is. For a comic strip character, Popeye is, in his earliest incarnation, surprisingly recognizable to us: those misshapen forearms and calves, that “shipwreck” of a face (as Olive Oyl calls it), his squinty brow and enormous chin are already present and instantly iconic in the first panel. To paraphrase Popeye’s own mangled, existential cry: He is what he is — but is that all he is?
“I don’t need no reason,” he replies. “I socks ’em where I sees ’em, an’ I leaves ’em where I socks ’em — an’ tha’s that.” O.K., then.
He’s not exactly a funny animal, but a kind of noble beast that Castor is constantly trying to civilize. From the beginning, Popeye’s and Castor’s seesawing contempt and affection for each other made them a great comic duo: the schemer and the muscle. But they are doomed. Each time Castor calls Popeye from the docks to send him to a tutor or invites him to join his detective agency, Popeye inevitably fouls up his friend’s charity by socking someone in the face.
What Castor doesn’t seem to notice is that Popeye eventually stops going back to the docks. Suddenly he’s living with the Oyls, moving in on Olive’s affection and taking over the whole strip. Within a year, the sheer force of his “personaliky” would cast the decade’s worth of “Thimble Theatre” strips that preceded him so thoroughly into the realm of trivia that they aren’t even collected here. In some ways this is precisely the bit of lost history Deitch hopes to preserve: scanned from original newspaper clippings that otherwise had been yellowing somewhere or another, this book documents not only the birth of a great American comic character, but also, in a smaller measure, the death of a great straight man.