Musicians/bands that make (or have made) music based on history or ancient mythology

EX DEO: a death metal band that specializes in music all about ancient Rome and Roman mythology.

Sabaton: power metal band whose songs are all about historical battles and warfare.

Fleshgod Apocalypse: another death metal band, their album "Labyrinth" was a concept album based around Greek myths associated with the Labyrinth of Knossos.

Septic Flesh: An atmospheric/symphonic death metal from Greece who's lyrics are mostly mythology based, sometimes historical or even sci-fi.

E.S. Posthumus: A music group that made orchestral and ambient music. Their most well known work is in there album "Unearthed". Each track is named after ancient cities of the past, which I think is supposed to relate with the nature of each one.

Can't have a thread like this without mention of Nile, a death metal band that mixes both technicality and brutality to create awesomeness. Their songs are mainly about Ancient Egyptian history/customs and the mythology of the civilization. They also occasionally write songs about the Lovecraft Universe.