The Battle of Mardia, also known as Battle of Campus Mardiensis or Battle of Campus Ardiensis, was probably fought at modern

Harmanli Harmanli ( bg, Харманли , tr, Harmanlı) is a town in Haskovo Province, south-central Bulgaria. It is the administrative centre of the eponymous Harmanli Municipality. Near the site of Hamanli in Late Antiquity, during the early 4th- ...

(

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...

) in

Thrace Thrace (; el, Θράκη, Thráki; bg, Тракия, Trakiya; tr, Trakya) or Thrake is a geographical and historical region in Southeast Europe, now split among Bulgaria, Greece, and Turkey, which is bounded by the Balkan Mountains to ...

,N.E. Lenski 2006, p.74 in late 316/early 317 between the forces of Roman Emperors

Constantine I Constantine I ( , ; la, Flavius Valerius Constantinus, ; ; 27 February 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337, the first one to convert to Christianity. Born in Naissus, Dacia Mediterran ...

and

Licinius Valerius Licinianus Licinius (c. 265 – 325) was Roman emperor from 308 to 324. For most of his reign he was the colleague and rival of Constantine I, with whom he co-authored the Edict of Milan, AD 313, that granted official toleration to C ...

Background

Open civil war between Constantine and Licinius broke out in 316 when the former invaded Licinius' Balkan provinces. After his crushing defeat at the Battle of Cibalae on October 8, 316, (some historians date it in 314), Licinius fled to

Sirmium Sirmium was a city in the Roman province of Pannonia, located on the Sava river, on the site of modern Sremska Mitrovica in the Vojvodina autonomous provice of Serbia. First mentioned in the 4th century BC and originally inhabited by Illyria ...

then further south to Adrianople. There he collected a second army, under the command of an officer named

Valerius Valens Aurelius Valerius Valens (died 317), rarely Valens I, was briefly Roman emperor from late 316 to early 317. He was proclaimed emperor by Licinius, emperor of the East, during his war against Constantine I, emperor of the West. Biography In ...

whom he raised to the rank of Augustus. Simultaneously, he tried to negotiate with Constantine but the latter, insulted by the elevation of Valens and confident from his recent victory, rejected the peace offer.

The battle

In the meantime, Constantine had moved through the

Balkan The Balkans ( ), also known as the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throughout the who ...

mountains and established his base at

Philippi Philippi (; grc-gre, Φίλιπποι, ''Philippoi'') was a major Greek city northwest of the nearby island, Thasos. Its original name was Crenides ( grc-gre, Κρηνῖδες, ''Krenides'' "Fountains") after its establishment by Thasian colo ...

or Philippopolis. He then led the bulk of his army against Licinius. In the ensuing fierce battle, both sides inflicted heavy injuries on each other until darkness interrupted the indecisive struggle. Reportedly, Constantine decided the issue by sending a force to attack Licinius in the rear, forcing him to retreat. However, his well-disciplined troops kept ranks, withdrawing in good order, and both sides suffered heavy losses as Constantine brought his forces to bear, hoping to crush the enemy. During the night, Licinius managed to keep his army from disintegration and retreated north-west towards Beroe/Augusta Traiana. Thus, Constantine was again victorious but not decisivelyD.S. Potter 2004, p. 378 Another possible location for the battle place is a few km west-southwest of Adrianople (modern

Edirne Edirne (, ), formerly known as Adrianople or Hadrianopolis ( Greek: Άδριανούπολις), is a city in Turkey, in the northwestern part of the province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders ...

), at the basin of the Ardas RiverC. Odahl 2004, p.164 (ancient Harpessos), a tributary of the

Maritsa Maritsa or Maritza ( bg, Марица ), also known as Meriç ( tr, Meriç ) and Evros ( ell, Έβρος ), is a river that runs through the Balkans in Southeast Europe. With a length of ,Byzantium Byzantium () or Byzantion ( grc, Βυζάντιον) was an ancient Greek city in classical antiquity that became known as Constantinople in late antiquity and Istanbul today. The Greek name ''Byzantion'' and its Latinization ''Byzantium' ...

in order to retreat to his Asian base, headed to that direction, unintentionally placing Licinius between himself and his communication lines with the West. It seemed that his aggressiveness had turned against him this time. However, both belligerents had reasons to come to terms since Licinius was still in precarious position, so he sent a certain Mestrianus to negotiate with Constantine.C. Odahl 2004, 165 Even then, Constantine delayed the discussions until he was made sure that the outcome of the war was indeed uncertain. A critical point might be when he received news of a sudden enemy raid that captured his baggage and the royal entourage.Petrus Patricius, '' Excerpta de legationibus ad gentes'' at N.C. Lieu, D. Montserrat, pp.57-58 According to the peace finalized at

Serdica Serdika or Serdica ( Bulgarian: ) is the historical Roman name of Sofia, now the capital of Bulgaria. Currently, Serdika is the name of a district located in the city. It includes four neighbourhoods: "Fondovi zhilishta"; "Banishora", "Orlandov ...

on 1 March 317 (a date chosen deliberately by Constantine because it was the anniversary of his father's elevation), Licinius recognised Constantine as his superior in government, ceded to him all European territories except for

and deposed and executed Valens. Constantine named himself and Licinius

consul Consul (abbrev. ''cos.''; Latin plural ''consules'') was the title of one of the two chief magistrates of the Roman Republic, and subsequently also an important title under the Roman Empire. The title was used in other European city-states throu ...

s while his two sons

Crispus Flavius Julius Crispus (; 300 – 326) was the eldest son of the Roman emperor Constantine I, as well as his junior colleague ( ''caesar'') from March 317 until his execution by his father in 326. The grandson of the ''augustus'' Constantius ...

and Constantine II and Licinius' son, also called

, were all appointed Caesars. The peace lasted for about seven years.

Citations

References

Anonymus Valesianus. ''Origo Constantini Imperatoris''
at The Latin Library *

Eusebius Eusebius of Caesarea (; grc-gre, Εὐσέβιος ; 260/265 – 30 May 339), also known as Eusebius Pamphilus (from the grc-gre, Εὐσέβιος τοῦ Παμφίλου), was a Greek historian of Christianity, exegete, and Chris ...

. ''Life of Constantine'', transl. and commentary by Averil Cameron, Stuart George Hall, Oxford University Press, 1999. . * Lieu, Samuel N. C., Montserrat, Dominic. ''From Constantine to Julian: A Source History'', Routledge, 1996. * Lenski, N. E. ''The Cambridge Companion to the Age of Constantine,'' Cambridge University Press, 2006. * Odahl, Charles M. ''Constantine and the Christian Empire'', Routledge, 2004. * Potter, David S. ''The Roman Empire at Bay AD 180–395'', Routledge, 2004. * Treadgold, Warren. ''A history of the Byzantine State and Society'', Stanford University Press 1997. * Zosimus, ''Historia Nova'' ( Greek: ''Νέα Ιστορία''), book 1, in ''Corpus Scriptorum Historiae Byzantinae'', ed. Bekker, Weber, Bonn, 1837 {{coord, 41, 56, N, 25, 54, E, type:event_region:BG_scale:2000000, display=title Mardia Mardia Mardia 316 310s in the Roman Empire