Constantius II

Constantius II (324-361 CE) was a Roman Emperor and part of the Constantine Dynasty.

1. BIOGRAPHICAL DETAILS

NAME:
- Flavius Julius Constantius
CONSTANTIUS II’ DATE OF BIRTH AND DEATH:
- Born: 7 August 317 CE. Died 3 November 361 CE.
PLACE OF BIRTH AND DEATH:
- Born in Sirmium, Pannonia Superior. Died in Cilicia.
CONSTANTIUS II’ PREDECESSOR:
- Constantine I
CONSTANTIUS II’ SUCCESSOR:
- Julian
CONSTANTIUS’ DATES OF REIGN AS EMPEROR:
- 324 to 337 CE as Co-Emperor (Caesar) with his father Constantine I.
- 337-340 CE as Co-Emperor with his brothers Constantine II and Constans.
- 340-350 CE as Co-Emperor of the East with his brother Constans in the West.
- 350-361 CE as sole Emperor of the Roman Empire.
HEIR TO THE THRONE BECAUSE:
- His father was Constantine I who made all three of his sons co-Emperors.
DIED PEACEFULLY OR ASSASSINATED:
- Died after of a fever, just as he was about to go to war against Julian.
WHERE BURIED:
- Church of the Holy Apostles, Constantinople.
CONSTANTIUS WAS FAMOUS BECAUSE:
- He was a member of the Constantine Dynasty.

When Constantine I died in 337 CE, the Empire was split between his three sons and two cousins. The cousins were immediately massacred by Constantius II in Constantinople, leaving the three brothers in charge.
On the 9 September 337 CE, Constantine II, Constans and Constantius II met at Sirmium in Pannonia and divided the Empire between themselves.
1. Constantine II received Hispania, Gaul, Britannia and Mauretania
2. Constantius II received the eastern Provinces of Constantinople, Thracia, Asia Minor, Syria, Egypt, Cyrenaica
3. Constans received Italia, Africa Proconsularis, Illyricum, Thracia, Pannonia, Macedonia and Achaea.

Constantine II was the Guardian of his younger brother Constans. When Constans reached 21, he refused to hand over power, and ordered Constans to relinquish his African Provinces. In the disagreement that followed, Constantine II decided to invade Italia. Constans was in Dacia and sent an army to intercept his brother.
Constantine II was ambushed at Aquileia and killed, with Constans inheriting all his territories.

Between 340 to 350 CE, Constans ruled in the West, whilst Constantius II ruled in the East.

Earlier, Constantine II had returned the Trinitarian, Athanasius to Alexandria in Egypt, much to the annoyance Constantius II, who supported Arianism.
After Constans had replaced Constantine II in the West, the two remaining brothers could not agree over the dominance of Arianism or the Nicene Creed.

In 343 CE Constans summoned the Council of Sardica to resolve the dispute between Arianism and Nicene Creed, but without success.
In 346 CE, to avoid war between the brothers, each agreed that Arianism should continue under Constantius II in the East, and the Nicene Creed should continue under Constans in the West.

In 337 CE, taking advantage of Constantine I‘ death, King Shapur II of the Sassanid Empire invaded Mesopotamia with an army using War Elephants, and besieged Nisibis.
Constantius II repelled the attack, but the decade was characterised by repeated Sassanid sieges of major Roman forts, such as Nisibis, Singara and Amida.

Before he departed to suppress the rebellion by Magnentius, Constantius II married his sister, Constantina, to his cousin, Constantius Gallus, and promoted him to Caesar.
Vetranio, the Commander of Illyricum, had proclaimed himself Augustus, but when Constantius II arrived, he resigned his claim and was retired honourably.

In 351 CE, Constantius II defeated Magnentius at the Battle of Mursa Major which was the bloodiest battle in the history of the Roman Army. Magnentius lost two thirds of his army and Constantius II lost half, a total of 50,000 men.

Magnentius withdrew to Italia. Constantius remained on the Danube to campaign against the Sarmatians.
In 352 CE, Constantius II invaded Italia, and Magnentius‘ armies changed sides and left him. Magnentius escaped to Gaul.
In 353 CE, Constantius II again defeated Magnentius at the Battle of Mons Seleucus. Realising that further conflict would not succeed, Magnentius committed suicide on 10th August.

In 353 CE and 354 CE, Constantius II was forced to campaign against the Alemanni.
In 354 CE Constantius II made peace with the Alemanni, and returned to Milan. Concerned about a rebellion in the East, Constantius II summoned Gallus and his sister Constantina, who died during the journey. When Gallus reached Pannonia he was arrested and eventually executed, despite being pardoned.

Silvanus had surrendered to Constantius II after the Battle of Mons Seleucus, and been given the Rhine command as Magister Militum. Aware of a plot against himself, orchestrated by Constantius II, Silvanus proclaimed himself Emperor on 11 August 355 CE in Cologne.
Ursicinus, the commander already sent to replace Silvanus, outwitted Silvanus and had him executed.
Ammianus Marcellinus considers Silvanus was innocent, and the victim of a vicious plot by a rival general.

On 6 November 355 CE, Constantius II promoted his cousin Julian to Caesar and married his last sister Helena to him, then sent him to Gaul.
Still ruling from Milan, Constantius II was forced to campaign against the Sarmatians and the Quadi.

In 357 CE, Shapur II sent ambassadors to Constantius iI to demand Rome return Persian lands that they had previously surrendered. Unwilling to re-engage in warfare, Constantius II negotiated for two years, but finally in 359-360 CE, Shapur II invaded Mesopotamia anyway.

Constantius was forced to amass a large army for the war, and requested Julian send his Legions. The army rebelled and proclaimed Julian as Emperor.
In 361 CE, torn between fighting the Sassanids and subduing Julian, Constantius remained in the East, using diplomacy to persuade Julian. However, he failed to retake the fortresses lost to Shapur II, and withdrew to Antioch.

Encouraged by a decline in Sassanid hostilities, Constantius II decided to turn west and suppress Julian‘s rebellion.
He set off and reached Cilicia, but realising he had contracted a fatal illness, adopted Julian as his heir instead.
He died of a fever on 3 November 361 CE

CLASSICAL SOURCES:
- Zosimus Historia Nova
- Eutropius Breviarium Historiae Romanae
- Ammianus Marcellinus Roman History