Gallienus, Latin in full Publius Licinius Egnatius Gallienus, (born c. 218—died 268), Roman emperor jointly with his father, Valerian, from 253 until 260, then sole emperor to 268. Gallienus ruled...
Gallienus, Latin in full Publius Licinius Egnatius Gallienus, (born c. 218—died 268), Roman emperor jointly with his father, Valerian, from 253 until 260, then sole emperor to 268. Gallienus ruled an empire that was disintegrating under pressures from foreign invaders.