Northern Africa 320: Constantine and Licinius
The Battle of the Milvian Bridge established Constantine’s power over the western Roman Empire and in 313 Licinius defeated Maximinus Daza to become sole emperor in the east. Despite several clashes, the empire remained divided between the two emperors for over a decade until Constantine’s final defeat of Licinius in 324.
30 Apr 313 Battle of Tzirallum▲
In the spring of 313, while Licinius was still at Mediolanum, Maximinus Daza crossed the Hellespont with 70,000 men and captured Byzantium and Heraclea Perinthus. When he heard the news of the invasion, Licinius raced east to Adrianople, assembling a force of 30,000 men along the way. The two armies met at Tzirallum (Corlu) in late April, where, despite being severely outnumbered, Licinus’ veteran troops routed their opponents and compelled Maximinus to flee to Asia.
315?–320? All Arab expansion south▲
At some point in his reign, possibly during the late 310s, Imru al-Qays ibn Amr, the Lakhmid King of All Arabs, brought the central Arabian polity of Ma’ad under his power. From here, he expanded south to conquer the kingdoms of Nizar and Kinda, driving the Kindites “to the gates of Najran” in Himyarite territory.
8 Oct 316 Battle of Cibalae▲
In early October 316 Constantine led a force of as few as 20,000 infantry and cavalry across Pannoniae, where he met an army of 35,000 under Licinius at Cibalae. Constantine attacked with his cavalry at dawn but the fighting continued until nightfall, when he managed to break through with his right wing. Having sustained losses of some 20,000 infantry, Licinius abandoned his camp and fled under cover of darkness with his own cavalry to Thrace via Sirmium, destroying bridges along the way.
10 Nov 316–? ?? 321 Donatist Controversy▲
In 311 the moderate Christian Caecilian was appointed as bishop of Carthage, a move strongly opposed by the more fanatical rigorists, who instead consecrated their own bishops: first Majorinus and then, in 313, Donatus Magnus, after whom the sect would be named the Donatists. After repeated calls for compromise only exacerbated Donatist unrest and riots in Africa, Constantine ordered the confiscation of Donatist property and the exile of their leaders. The persecution peaked in 317, when imperial troops stormed a Donatist church in Carthage and massacred the congregation, but was revoked by Constantine four years later.
317 Battle of Mardia▲
In early 317 Constantine marched from Philippopolis towards Adrianople, approaching the encampment of Licinius and Valens on the plain of Mardia. The two armies engaged at dawn and fought for many hours, before a force of 5,000 that Constantine had earlier detached turned the tide of the battle by arriving on Licinius’ flank. Even so, Licinius’ troops held their ground until nightfall could aid their escape, leaving the battlefield with many thousands of dead from both sides.
1 Mar 317 Peace of Serdica▲
Following the Battle of Mardia, Constantine pushed on east, towards Byzantium, but Licinius, anticipating this move, instead moved northwest to Augusta Traiana and cut Constantine’s supply line. Rather than risk all he had achieved, Constantine accepted Licinius’ offer to a truce. In a treaty signed at Serdica (Sofia, Bulgaria) in March 317, the two Augusti agreed to resume their alliance, while Licinius acknowledged Constantine’s gains by ceding Europe west of Thracia to him. Constantine and Licinius also named their infant sons, Constantine II and Licinius II, and Constantine’s teenage son Crispus as Caesars.