Gaius Messius Quintus Traianus Decius, Roman emperor 249–251. Born ca. 200 near Sirmium in Pannonia, he became one of the most influential senators of his time. In 248 the emperor Philip sent him to the eastern frontier along the Danube, an area he knew well and which was deeply troubled: the usual pressure of the Goths was increased in 248 by the mutiny of the legions of Moesia and Pannonia. Acclaimed emperor by the army, he attacked and defeated Philip at Verona 249. With him began the series of Illyrican emperors who tried to restore the power of Rome, torn by military anarchy. Convinced that to achieve this purpose he had to restore the republican and imperial tradition and reinvigorate the old religion, he took various measures, including one that particularly affected Christians. Late in 249 he issued a general edict ordering Roman citizens to participate in a supplicatio, consisting of offerings of incense, libations and consumption of sacrificial meat, to show their loyalty to the dei publici. This was the first general edict in the history of the empire to strike at all Christians the credibility of a passage in the Historia Augusta Sparziano, Sept. Sev. 17,1, according to which an earlier general edict of Septimius Severus had forbidden Jewish and Christian proselytism, is still disputed.
Decius’s intention does not seem to have been to make martyrs, but apostates. Many Christians defected, some by performing the required sacrifice in full sacrificati, some merely burning a few grains of incense thurificati, others purchased the libellus issued by special commissions libellatici, and finally others yielded to threats or torture. Many, on the other hand, held firm to their faith and were killed, among them bishops Fabian of Rome see Liber Pontificalis, ed. Duchesne, I, 4; Euseb., HE VI, 39,1, Alexander of Jerusalem see Euseb., HE VI, 39,2-3 and Babylas of Antioch see Euseb., HE VI, 39,4. Even Origen, arrested at Caesarea of Palestine where he was teaching, was tortured and later died from the effects. Cyprian of Carthage, judging it necessary to continue guiding his church, which was undergoing a very difficult period because of the persecution, retired to a safe place from where he maintained contact with his flock. In his treatise on the apostates De lapsis he recounts the experience and, while praising the martyrs and confessors who survived the test, does not ignore the problems, including disciplinary, created by Christians who had denied the faith.
After about a year late 250 the persecution had lost its intensity; by spring 251 it seems to have been spent. In the meantime, Decius had to face a particular threat to Moesia by the Goths and Carpi. Insufficiently supported or perhaps betrayed by the regional Roman military commander Trebonianus Gallus who succeeded him as emperor, Decius was defeated and killed in the swamps of Abrittus, in present-day Dobruja Romania, in early summer 251. Despite his efforts to forcefully impose loyalty to the pagan tradition on his subjects papyri preserve Egyptian libelli from June-July 250 with the prescribed formula of loyalty, Decius’s religious policy, in particular toward Christians, did not achieve the hoped-for results and, despite the defections, it seems in a way to have tempered the churches in preparation for the trials of the coming years.