What historical figures are depicted on this Ostby & Barton ring? (pic inside)

by curitibano

Hi, my father and I can't come to a conclusion as to what kind of helmet is being worn on this ring. I think it's a Spanish conquistador, while he thinks it's a Roman Royal Guard. Can anyone of you historical geniuses clear it up for us to give us peace of mind?

https://imgur.com/a/PoYR2

TywinDeVillena

What other elements are shown on the ring? Just by looking at it, I can tell you that the man with the beard looks like a Roman general. The other one looks like an ordinary Roman fellow. Without any more data, that's why I can tell you.