He may have assumed the title of king before; but he now became totius Orientis imperator, not indeed joint-ruler, nor Augustus, but independent lieutenant of the emperor for the East (Mommsen, Provinces, ii. p. 103).
He was the nephew (according to Zonaras xii.24) or the cousin (according to Historia Augusta, which lists him among the Thirty Tyrants) of Odaenathus, who had taken control of the Eastern provinces after the defeat and capture of Emperor Valerian by Shapur I of the Sassanid Empire.