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.
In the nativities and questions of men, make , and , and their directions; chiefly, in questions concerning kings and great persons, by which their accidents are chiefly known, let them be good, or evil. - William Lilly (1602.-1681.)