I'm writing an essay regarding the Shakespearean play Othello and I was intending to make a point out of how it occurs in two locations, one may be symbolic of home, whilst the other of the unknown. My question is, prior to the beginning of the Renaissance (15th century), how much adventuring was occurring? I intend to draw upon how perhaps Shakespeare's symbolism was inspired by the influx of adventure during the Renaissance by the likes of people such as Cristopher Columbus. If anyone has any recommendation as to some other adventurers that would perhaps fit the bill nicely then I'd be grateful to hear about them, mainly because I'm most likely incredibly misinformed and there are some other genuine reason behind Shakespeare's choice of plot location.

Edit I would like to make: I've realised now that "maritime explorer" is probably a more suitable word for an essay.