Decius in the context of "Persecution of Christians in the Roman Empire"

Philip I (Latin: Marcus Julius Philippus; c. 204 – September 249), commonly known as Philip the Arab, was Roman emperor from 244 to 249. After the death of Gordian III in February 244, Philip, who had been Praetorian prefect, rose to power. He quickly negotiated peace with the Sasanian Empire and returned to Rome to be confirmed by the Senate. According to many historians, he was possibly the first Christian Roman Emperor.

Although his reign lasted only five years, it marked an unusually stable period in a century that is otherwise known for having been turbulent. Near the end of his rule, Philip commemorated Rome's first millennium. In September 249 he was killed during or shortly after the Battle of Verona against the usurper Trajan Decius, who was subsequently recognized by the Senate as his successor.

The antoninianus or pre-reform radiate was a coin used during the Roman Empire thought to have been valued at 2 denarii. It was initially silver, but was slowly debased to bronze with a minimal silver content. The coin was introduced by Caracalla in early 215 AD. It was silver, similar to the denarius, except that it was slightly larger and featured the emperor wearing a radiate crown, indicating it was a double denomination. Antoniniani depicting women (usually the emperor's wife) featured the bust resting upon a crescent moon.

Even at its introduction, the silver content of the antoninianus was only equal to 1.5 denarii. This created inflation: people rapidly hoarded the denarii (Gresham's law), while both buyers and sellers recognized the new coin had a lower intrinsic value and elevated their prices to compensate. Silver bullion supplies began running short because the Roman Empire was no longer conquering new territory, the Iberian silver mines had been exhausted, and a series of soldier emperors and usurpers needed coin to pay their troops and buy their loyalty. Each new issue of the antoninianus thus had less silver in it than the last, and thus contributed to ever-increasing inflation.

The Battle of Verona was fought between the Roman general and usurper Decius, and emperor Philip the Arab in 249. Decius was victorious and Philip and his son Philip II were both killed. Decius was subsequently declared Roman emperor.

Pacatianus, known in English as Pacatian (/ˈpəkeɪʃ(i)ən/; Latin: Tiberius Claudius Mar[...] Pacatianus; died c. 248) was a usurper in the Danube area of the Roman Empire during the time of Philip the Arab. His praenomen and nomen suggest his ancestors obtained Roman citizenship either during the time of Tiberius or of Claudius.

His life is known from mentions in the histories of Zosimus and Zonaras. However, the chronology of these accounts is obscure, and modern scholars use coinage to establish the timeline of his life and revolt. Zonaras names him as a 'unit commander' of one of the Danube legions, possibly Legio VII Claudia. He was likely a leader in the effort to drive Gothic invaders out of Roman territory in 248, one of the first actions of the Gothic War. Either during this action or soon after he was acclaimed emperor by the Danube legions. Eventually his control extended to the city of Viminacium. According to Zosimus, the news of Pacatian's revolt in Moesia and of Jotapian's near-simultaneous revolt in Syria prompted Philip to make an offer to the Roman Senate to step down. Both Zosimus and Zonoras relate that Philip was advised by the senator Decius, who predicted that Pacatian would soon be killed by his troops. This soon came to pass, and Philip (over Decius' objections) sent Decius to the Danube to find out the causes of the revolt. Decius was promptly acclaimed as emperor by the legions on the Danube, and (though Zonaras records that Decius offered to resign) eventually overcame Philip by the end of 249.

Christians were persecuted in 250 AD under the Roman emperor Decius. He had issued an edict ordering everyone in the empire to perform a sacrifice to the Roman gods and the well-being of the emperor. The sacrifices had to be performed in the presence of a Roman magistrate, and be confirmed by a signed and witnessed certificate from the magistrate. Although the text of the edict has been lost, many examples of the certificates have survived.

Decius' edict was intended to act as an empire-wide loyalty oath to the new emperor (who had come to power in 249 AD), sanctified through the Roman religion. Christian monotheistic beliefs did not allow them to worship any other gods, so they were forced to choose between their religious beliefs and following the decree.

The Diocletianic or Great Persecution was the last and most severe persecution of Christians in the Roman Empire. In 303, the emperors Diocletian, Maximian, Galerius, and Constantius issued a series of edicts rescinding Christians' legal rights and demanding that they comply with traditional religious practices. Later edicts targeted the clergy and demanded universal sacrifice, ordering all inhabitants to sacrifice to the Roman gods (Jews were exempt). The persecution varied in intensity across the empire—weakest in Gaul and Britain, where only the first edict was applied, and strongest in the Eastern provinces. Persecutory laws were nullified by different emperors (Galerius with the Edict of Serdica in 311) at different times, but Constantine and Licinius' Edict of Milan in 313 has traditionally marked the end of the persecution.

Christians had been subject to intermittent local discrimination in the empire, but emperors prior to Diocletian were reluctant to issue general laws against the religious group. In the 250s, under the reigns of Decius and Valerian, Roman subjects including Christians were compelled to sacrifice to Roman gods or face imprisonment and execution, but there is no evidence that these edicts were specifically intended to attack Christianity. After Gallienus's accession in 260, these laws went into abeyance. Diocletian's assumption of power in 284 did not mark an immediate reversal of imperial inattention to Christianity, but it did herald a gradual shift in official attitudes toward religious minorities. In the first fifteen years of his rule, Diocletian purged the army of Christians, condemned Manicheans to death, and surrounded himself with public opponents of Christianity. Diocletian's preference for activist government, combined with his self-image as a restorer of past Roman glory, foreboded the most pervasive persecution in Roman history. In the winter of 302, Galerius urged Diocletian to begin a general persecution of the Christians. Diocletian was wary and asked the oracle at Didyma for guidance. The oracle's reply was read as an endorsement of Galerius's position, and a general persecution was called on 23 February 303.

Quintus Herennius Etruscus Messius Decius (died c. June 251), known simply as Herennius Etruscus, was briefly Roman emperor in 251, ruling jointly under his father Decius. His father was proclaimed emperor by his troops in September 249 while in Pannonia and Moesia, in opposition to Philip. Decius defeated Philip in battle, and was then proclaimed emperor by the Senate. Etruscus, still a child, was elevated to Caesar (heir) in 250, then further raised to Augustus (emperor) in May 251. When the Goths, under Cniva, invaded the Danubian provinces, he was sent with a vanguard, followed by the main body of Roman troops, led by Decius. They ambushed Cniva at the Battle of Nicopolis ad Istrum in 250, routing him, before being ambushed and routed themselves at the Battle of Beroe. Etruscus was killed in the Battle of Abritus the following year, alongside his father. After the deaths of both emperors, Trebonianus Gallus, who had been governor of Moesia, was elected emperor by the remaining Roman forces.