Europe 337: Sons of Constantine
In late 336 Constantine began preparing for war with Persia, but only made it as far as the vicinity of Nicomedia when he fell ill. After his death in May 337, the army rallied behind his three sons—Constantine II, Constantius II, and Constans—and proclaimed them co-emperors.
336 Overthrow of Khosrov the Small▲
Apparently concerned about the alliance between the Christian rulers of Rome and Armenia, Shapur II, shah of Sasanian Persia, sent his general Narseh to invade Armenia in 336. Many Armenians were Zoroastrian or otherwise pro-Persian and welcomed Narseh, who quickly captured the Armenian king Khosrov III the Small and replaced him with a Persian client. At about the same time, Vache I, the Arsacid king of Albania, abandoned the Romans and became a vassal of Shapur.
336 Battle of Narasara▲
After conquering Armenia in 336, the Persian general Narseh crossed into Roman territory and took the fortified settlement of Amida by storm. He then advanced into Roman Mesopotamia but was soon defeated and killed by Constantius II at nearby Narasara. After this, Constantius retook Amida and restored the frontier.
In response to the Persian conquest of Armenia in 336, Constantine began preparing for war. In early 337 he bestowed on his nephew Hannibalianus the title of Rex Regum et Ponticarum Gentium (“King of Kings and king of the Pontic Peoples”), apparently in order to set him up as the future Roman ruler of Persia and Armenia.
22 May 337 Death of Constantine the Great▲
In spring 337, shortly after departing Constantinople to begin his war with Persia, Constantine fell ill. At the villa of Achyron, near Nicomedia, he was baptized by the Arian bishop Eusebius of Nicomedia and then died. His body was transferred back to Constantinople, where he was buried in the Church of the Holy Apostles, surrounded by the memorial steles of the Twelve Apostles.
May–Sep 337 Constantius II’s Purge▲
When he heard of Constantine’s death in May 337, Constantius II raced to Constantinople. Upon his arrival, the imperial troops seem to haven risen against Constantine’s nephews Dalmatius and Hannibalianus, who had been earmarked by Constantine to be co-emperors with the sons of Constantine. A purge followed in which Dalmatius and Hannibalianus were killed, alongside their father Flavius Dalmatius, Constantine’s other half-brother Julius Constantius, and other relatives. Prominent members of the court and the Church were also executed. By the end of the year only six male members of the Constantinian dynasty remained: the three sons of Constantine and three of his nephews (Gallus, Julian, and Julius Nepotianus).
337 Shapur II’s First Siege of Nisibis▲
Learning of Constantine’s death in 337, the Persian shah Shapur II invaded Roman Mesopotamia with a large force—infantry, cavalry, and war elephants—and besieged the strategic city of Nisibis. Persian engineers redirected the river Mygdonius, which smashed through the walls of Nisibis and flooded parts of the city. Encouraged by Bishop Jacob of Nisibis, the Roman defenders worked overnight to block the breaches and the next day repelled the Persian attack. With his efforts defeated, Shapur II lifted the siege and withdrew.
337 Constantius II’s First Sarmatian Campaign▲
Following the death of Constantine and the overthrow of Dalmatius in 337, the Sarmatians asserted their independence from Rome. Constantius II, who was marching through the Balkans to establish his control in Dalmatius’ former realm, fought and presumably defeated them by September.
9 Sep 337 Sons of Constantine▲
During the purge following the death of his father Constantine in May 337, the 20-year-old Constantius II seized control of the deposed Dalmatius’ territory in the Balkans. In September his two brothers Constantine II and Constans—in control of Gaul and Italy respectively—met with him in Pannoniae, where all three were proclaimed joint Augusti by the army and part of Constantius’ gains in the Balkans were ceded to Constans. However, as Constans was at the time only about 14, he was initially under the guardianship of the 21-year-old Constantine.