So here's a question about Iago, maybe somebody familiar with the history of the play (specifically the military aspect) can answer.
I'd always assumed, based on their number of interactions, that Iago was something of a "right hand man" to Othello. A high ranking officer, who'd been in a position to compete for promotion(1) with Cassio - and lost.
However, when I went looking up that word that Iago is always called - Othello's "ancient(2)" - doesn't mean what I think it means. Inconceivable.
"Ancient" apparently means something along the lines of "flag-bearer", if I'm reading the resources correctly? is that true? Doesn't that seem like it would be ... I don't know, a fairly minor rank? Independent of the play, if somebody asked me whether flag-bearers were typically friends with generals, I'd have to say "no way". I guess I'd always just assumed that ancient meant something more akin to how Jean Luc Picard always used to call Riker his "number 1". Shows what I know. Nobody's actually trusting what I say here, right? :)
(1) Props to the one summary site I visited that told me ancient is "a rank below lieutenant", one of those answers that is simultaneously exactly right (since we know he was not *promoted* to that rank, he must be below it) and yet completely useless.
(2) On one of those "we'll sell you a Shakespeare essay" sites I stumbled across, it said that Iago "pretended to be Othello's ancient", showing a pretty bad misunderstanding of the character.