Constantine II (emperor)

Lore & Background

Constantine II was born in Arles in 317, the second son of Constantine I and probably the eldest with his wife Fausta. He was made caesar on 1 March 317 at Serdica. He accompanied his father on a campaign against the Sarmatians in 323 and was commemorated on coinage for the victory. By 328 his own court was installed at Trier. An inscription from 328–330 records the title Alamannicus, indicating a victory over the Alamanni. In 332 he served as field commander during a winter campaign against the Goths, which reportedly resulted in 100,000 Goths slain and the surrender of their ruler Ariaric. Festival games were initiated in Rome to celebrate his role. He was married prior to 336, though his wife's identity remains unknown; David Woods theorized she may have been a half-cousin, possibly a daughter of Julius Constantius, while Barnes suggested she could have been a daughter of Flavius Optatus.

Reader's Guide

Constantine II's significance lies in his brief and contentious reign as one of the three sons of Constantine I who divided the empire after their father's death. His belief in his rights of primogeniture led him to assert seniority over his youngest brother Constans, resulting in legislative intervention in Constans's territory and ultimately a failed invasion of Italy in 340, where he was killed in an ambush near Aquileia. After his death, he was subjected to damnatio memoriae: his acts were repealed, and he was branded 'the public enemy and our own enemy.' Later panegyrics omitted him entirely. His legacy is thus one of overreach and erasure, though his early military career and role in the massacre of relatives (ordered by his brother Constantius II) shaped the political landscape of the Constantinian dynasty.

Did You Know?

• Constantine II was made caesar at Serdica on 1 March 317, shortly after his birth.
• He held the consulship four times: in 320, 321, 324, and 329.
• After his death, Constans issued legislation repealing Constantine's acts, branding him 'the public enemy and our own enemy.'
• His wife's identity remains unknown; one theory suggests she may have been a granddaughter of Flavia Maximiana Theodora.

The Architecture of Shared Power

Diocletian's reimagining of imperial governance began not with four rulers but with two. In 285 he named the general Maximian as his caesar, a junior heir-apparent role, and elevated him to co-augustus the following year. The division was geographic: Maximian would oversee the western provinces while Diocletian administered the east. The symbolic language was deliberately mythological—the augustus was compared to Jupiter, his caesar to Hercules, the divine son. By March 293, Diocletian judged that the empire's civic and military pressures demanded more hands, so with Maximian's consent he added two further caesares: Galerius under the eastern augustus and Constantius under the western one. When both senior emperors retired together on 1 May 305, Constantius and Galerius stepped up to the top rank, and two fresh caesares—Valerius Severus in the west and Maximinus Daza in the east—filled the junior slots. For a brief, orderly span, the empire ran on this neat two-by-two grid.

The Unraveling

The carefully calibrated succession plan shattered almost immediately after Constantius's death in July 306. His son Constantine was proclaimed both augustus and caesar by his father's troops, a unilateral act that no one in the existing college had authorized. In the west, Maxentius challenged Severus's claim, took the title princeps invictus, and secured his own caesarship from his retired father Maximian. Severus capitulated to the pair by 307. Meanwhile Galerius, seeking to restore order, installed Licinius as western augustus in 308 and later raised Maximinus Daza to the same rank in 310. The empire now had more claimants than the original design allowed. Constantine's decisive victory over Maxentius at the Milvian Bridge in 312 gave him the west; the death of Maximinus left Licinius with the east. In March 317 the two surviving augusti jointly recognized their sons—Crispus, Constantine II, and Licinius II—as caesares, a gesture that preserved the old terminology even as the old structure was already dissolving. By 324, after the Battle of Chrysopolis, Licinius had resigned, and Constantine stood alone over the entire empire.

The Aftermath and Enduring Collegiate Tradition

Even after Constantine consolidated sole authority around 324, he did not abandon the language and practice of shared rule. He appointed his son Constantius II as caesar that same year, followed by Constans in 333 and his nephew Dalmatius in 335. When Constantine died in 337, his three surviving sons were declared joint augusti simultaneously, a direct echo of the earlier multi-ruler principle. The broader concept of dividing the empire among several co-emperors persisted for centuries, surviving all the way to the Fall of the Western Roman Empire. In the Eastern Roman Empire, the titles of augustus and caesar continued to be conferred sporadically long after the original four-person college had ceased to exist. The tetrarchic framework thus outlived its creator by many generations, morphing from a rigid two-by-two grid into a flexible tradition of collegiate sovereignty that shaped how the Roman state understood the distribution of supreme power.

What the Word Actually Meant

The label 'tetrarchy,' derived from the Greek for 'leadership of four,' was never actually applied to Diocletian's imperial college by the ancient authors who lived through it. In the classical usage, a tetrarchy described four independent rulers each governing a quarter of a divided kingdom—the most famous example being the post-Herodian tetrarchy of Judaea. Pliny the Elder captured the idea: each portion was 'the equivalent of a kingdom, and also part of one.' That conception of four sovereign, separate states stood in sharp contrast to the Diocletianic arrangement, which was a single college headed by one supreme leader. Ammianus recorded Constantius II invoking Diocletian's subordinates as models of obedience; Julian likened the tetrarchs to a chorus singing in unison under a conductor. Only Lactantius, a bitter ideological foe of the regime, treated them as a simple plurality of rulers. The term did not enter scholarly usage until Hermann Schiller in 1887, and it did not become standard until Otto Seeck adopted it in 1897.

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