The inscription was commissioned by Cyngen ap Cadell (died 855), king of Powys, in honour of his great-grandfather Elisedd ap Gwylog (reign 725–755), who is here claimed to be a descendant of "Britu son of Vortigern, whom Germanus blessed, and whom Sevira bore to him, daughter of Maximus the king, who killed the king of the Romans."[3]
The Pillar of Eliseg inscription is the only known source for a daughter of Magnus Maximus named Sevira (or Severa).
Further reading
Bartrum, Peter C. "SEVERA daughter of MAXIMUS.", in A Welsh Classical Dictionary: People in History and Legend up to about A. D. 1000, p. 236. National Library of Wales, 1993. Emended 2009, p. 672.
Charles-Edwards, T. M., Wales and the Britons, 350-1064, Oxford University Press, Oxford, 2013, p. 414ff.