Emrys is the Welsh form of the Latin Ambrosius, meaning immortal or enduring, a name tied in legend to a prophetic figure who influenced the Arthurian tradition. It suggests permanence -- something that outlasts its immediate moment rather than fading with circumstance.
Every city built with Mars in the Midheaven, or any other fixed star from the same nature, will see the majority of its governors die by the sword. - Ptolomeus