Editing 337 (section)

== Events ==
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=== By place ===

==== Roman Empire ====
* [[May 22]] &ndash; [[Constantine the Great]], first Christian [[Roman emperor]] of the Western Empire (312–324), and of the [[Roman Empire]] (324–337), dies in Achyron, near [[Nicomedia]], at age 65, after he is [[baptism|baptized]] by [[Eusebius of Nicomedia]].<ref>{{cite journal |doi=10.2307/300874 |jstor=300874 |title=The Last Days of Constantine: Oppositional Versions and their Influence |journal=Journal of Roman Studies |volume=84 |pages=146–170 |year=1994 |last1=Fowden |first1=Garth |s2cid=161959828}}</ref>
* [[September]] &ndash; A number of descendants of [[Constantius Chlorus]], and officials of the Roman Empire, are executed for a [[purge]] against the sons of [[Constantine I]].
* [[September 9]] &ndash; [[Constantine II (emperor)|Constantine II]], [[Constantius II]], and [[Constans]] succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three [[Augustus (honorific)|Augusti]] (see map).

==== Persia ====
* King [[Shapur II]] of [[Sasanian Empire|Persia]] begins a war against the Roman Empire. He sends his troops across the [[Tigris]] to recover [[Kingdom of Armenia (antiquity)|Armenia]] and [[Mesopotamia (Roman province)|Mesopotamia]].
* Shapur II besieges the Roman fortress of [[Nusaybin|Nisibis]] ([[Syria]]), but is repulsed by forces under Lucilianus.

==== China ====
* [[Murong Huang]] claims the title of [[Prince of Yan]], effectively beginning the kingdom of [[Former Yan]].

=== By topic ===

==== Religion ====
* [[February 6]] &ndash; A 4-month papal vacancy ends; [[Pope Julius I]] succeeds [[Pope Mark]], as the 35th pope.
* [[June 17]] &ndash; Constantius II announces the restoration of [[Athanasius of Alexandria|Athanasius]], as [[Patriarch of Alexandria]].
* [[Paul I of Constantinople|Paul I]] becomes [[Ecumenical Patriarch of Constantinople|Patriarch of Constantinople]].
* Christianity is declared an official religion in [[Kingdom of Iberia (antiquity)|Caucasian Iberia]], marking the rise of [[Christianity in Georgia (country)|Christianity in Georgia]].
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