Third century. Also known as Valerian I or Publius Licinius Valerienus. Emperor before October 253. Like the data for most of the Roman rulers of the troubled third century, the sources are less than adequate. Valerian would have been born near the beginning of the century, since at the time he became emperor, the son he associated with him, Gallienus (235-68), was already in his mid-thirties; Valerian must have been about sixty. He was from a noble family, and in the midst of the anarchical conditions of crisis from frontier assaults and internal disorder, he had already played important roles under preceding emperors. Under Decius (249-51), he was special finance officer, wherein he assisted in the efforts to compel by libelli revival of the state religion, which was the condition for the major persecution of the church. Under Gallus (251-53) he was military commander of troops from Raetia, but he was unable to prevent that emperor's death at the hands of soldiers in the conflict with the rival Aemilianus (253), who within three months met a similar fate when Valerian's troops made him the rival.
With his co-augustus he strove for stabilization, but the Goths and the Persians kept the fronts critical. Persecution of Christians remained severe under their joint administration; notable martyrs (258) include Sixtus II of Rome, his deacon Laurence and Cyprian of Carthage. But in the campaign on the Persian frontier, presumably by treachery, Valerian and his army were captured by Shapur I, a scene frequently cut in relief by the Persian. Neither the date of the disaster nor that of Valerian's subsequent death in captivity has been determined. But thereafter Gallienus brought a peace to the church which lasted for the next forty years, in spite of continuing internal revolt and strain on the frontiers.