If you’ve played or even heard a significant amount about a Final Fantasy game, you probably know about Cid. There are actually different Cids, one in each FF game except the first, and he was even sort of retconned into that one. I’ll say more on that later, though. For now, I’ll state that Cid is pretty much always an grandfatherly engineer and inventor, and at some point generally either builds or rebuilds at least one airship. He’s occasionally playable, but usually isn’t. I’d say FF6 is the first to really alter the character of Cid significantly, as here he really doesn’t have anything to do with airships, instead being a genetic engineer for the Empire who later defects and joins the Returners.
He’s the one who’s responsible for creating Magitek Knights by infusing people with power drained from Espers, with Kefka being the prototype who went crazy after the operation. He does discuss helping to rebuild Setzer’s airship, but as he wants to remove the casino, Setzer isn’t too keen on the idea. In FF7, Cid again has a connection to airships, but he’s much younger and crankier than the earlier Cids. Oddly, the other characters refer to him as an old man, when he’s actually only supposed to be in his thirties. But then, the FF games are full of really young heroes. I mean, Celes in FF6 is a general at the age of eighteen. I haven’t played the games beyond FF7, and while I can find descriptions of these Cids on the Internet, you can just as easily read about them yourself on the FF Wiki. I do find it interesting that FF12 has TWO Cids, the main one being a bad guy.
While Cid didn’t originally appear in FF1 (hey, they hadn’t thought of him yet), remakes of the game and Dissidia identify him as the Lufenian creator of the airship and the one who bred Chaos to serve as a living weapon. The inventor Otto in Mystic Quest was also retroactively dubbed a Cid, with his full name being Otto Cid Bekenstein.
So where does the name Cid come from? I don’t know for sure, but I have to wonder if it has anything to do with El Cid, an eleventh century Spanish military leader. There’s no direct connection, since El Cid wasn’t an engineer, but the spelling seems to me to suggest that he was indeed the namesake of the airship builders. Perhaps even more evidence is that the second Cid in FF12 is named Al-Cid Margrave. El Cid Campeador (literally “the lord champion” or “the master of martial arts”), whose real name was Rodrigo Díaz de Vivar, was a Castilian nobleman who led armies for both Castilian and Moorish kings. Eventually, he created his own largely independent state, with both Christians and Moors as subjects. He’s a legendary figure, and hence his being referenced in a video game series that has allusions to myths and legends throughout the world wouldn’t be too surprising.