Editing Constantius Chlorus (section)

===Early career===
Constantius's birthday was 31 March; the year is unknown, but his career and the age of his eldest son imply a date no later than c. 250.<ref name=barnes>{{cite book |last=Barnes |year=1982 |first=Timothy D. |title=The New Empire of Diocletian and Constantine |publisher=Harvard University Press |doi=10.4159/harvard.9780674280670 |place=Cambridge, MA |isbn=0-674-28066-0 |url=https://archive.org/details/barnes-new-empire|pages=4, 35}}</ref> Constantius was an [[Illyrians|Illyrian]].{{sfn|Odahl|2010|p=40}}<ref name="Murray221">{{harvnb|Murray|1999|p=221}}</ref>{{efn|On the other hand, [[Timothy Barnes (classicist)|Timothy Barnes]] argues that when ancient writers used the words [[Illyria|Illyricum]] and [[Thrace]]/[[Thracians]] to describe where Constantius came from, they were speaking of broad geographic terms rather than precise origins.{{sfn|Barnes|2011|p=[https://books.google.com/books?id=MwIiAgAAQBAJ&pg=PA30 30]}}}} He was born in [[Moesia Superior]] (later [[Dacia Ripensis]]),<ref name="ODB">{{Citation|last=Gregory|first=Timothy E.|author-link=Timothy E. Gregory|title=Constantius Chlorus|date=1991|url=https://archive.org/details/odb_20210521/page/524/mode/1up|work=[[Oxford Dictionary of Byzantium]]|editor-last=Kazhdan|editor-first=Alexander P.|editor-link=Alexander Kazhdan|publisher=Oxford University Press|doi=10.1093/acref/9780195046526.001.0001|isbn=978-0-19-504652-6|pages=524–525}}</ref>{{sfn|Barnes|2011|p=[https://books.google.com/books?id=MwIiAgAAQBAJ&pg=PA30 30]}} a [[Roman province#Late Antiquity|Roman province]] on the south bank of the [[Middle Danube]]. According to the unreliable ''[[Historia Augusta]]'' he was the son of Eutropius, a [[nobility|nobleman]] from the province of [[Moesia Superior]], and [[Claudia (mother of Constantius)|Claudia]], a niece of the emperors [[Claudius Gothicus]] and [[Quintillus]].<ref>''[[Historia Augusta]]'', ''Life of Claudius'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Claudius*.html#13 13]. [[LacusCurtius]].</ref> The same source also gives Claudius the nomina "[[Flavia gens|Flavius]] [[Valeria gens|Valerius]]" to strengthen his connection to Constantius.<ref>''[[Historia Augusta]]'', ''Life of Claudius'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Claudius*.html#13 1 (note 1)]. [[LacusCurtius]].</ref> Modern historians suspect this maternal connection to be a genealogical [[Lie#Fabrication|fabrication]] created by his son [[Constantine I (emperor)|Constantine I]],<ref>Southern, p. 172</ref> and that his family was of humble origins.{{sfn|Jones|Martindale|Morris|p=227}}<ref name="ODB" />{{efn|His family probably adopted the name "Flavius" after being granted citizenship by one of these emperors, as it was common for "new Romans" to adopt the names of their former masters.<ref name="names"/>}} Constantine probably sought to dissociate his father's background from the memory of Maximian.<ref name=":0">{{Citation|last1=Bond|first1=Sarah|title=Constantius I|url=https://research.vu.nl/files/248046167/Oxford_Dictionary_of_Late_Antiquity_cosmology.pdf|work=The Oxford Dictionary of Late Antiquity|year=2018|editor-last=Nicholson|editor-first=Oliver|publisher=Oxford University Press|language=en|doi=10.1093/acref/9780198662778.001.0001|isbn=978-0-19-866277-8|access-date=25 August 2020|last2=Nicholson|first2=Oliver|url-access=}}</ref>

[[File:Bronze-Flavia Maximiana Theodora-trier RIC 65.jpg|thumb|250px|Coin showing the ''Augusta'' Flavia Maximiana Theodora, Constantius's second wife, with the goddess ''[[Pietas (goddess)|Pietas]]'' on the reverse]]
Constantius was a member of the ''[[Protectores Augusti Nostri]]'' under the emperor [[Aurelian]] and fought in the east against the secessionist [[Palmyrene Empire]].<ref name="Potter, pg. 288">Potter, p. 288</ref> While the claim that he had been made a ''[[dux]]'' under the emperor [[Marcus Aurelius Probus|Probus]] is probably a fabrication,{{sfn|Jones|Martindale|Morris|p=228}}<ref>''[[Historia Augusta]]'', ''Life of Probus'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Probus*.html#22 22:3]. [[LacusCurtius]].</ref> he certainly attained the rank of ''[[tribunus]]'' within the army, and during the reign of [[Carus]] he was raised to the position of ''[[praeses]]'', or governor, of the province of [[Dalmatia (Roman province)|Dalmatia]].<ref>Odahl, Charles Matson. Constantine and the Christian Empire. New York: Routledge, 2004. p. 16</ref> It has been conjectured that he switched allegiances to support the claims of the future emperor [[Diocletian]] just before Diocletian defeated [[Carinus]], the son of Carus, at the [[Battle of the Margus]] in July 285.<ref>Potter, p. 280</ref>

In 286, Diocletian elevated a military colleague, [[Maximian]], to the throne as co-emperor of the western provinces,<ref name="Southern, pg. 142">Southern, p. 142</ref> while Diocletian took over the eastern provinces, beginning the process that would eventually see the division of the [[Roman Empire]] into two halves, a [[Western Roman Empire|Western]] and an [[Byzantine Empire|Eastern]] portion. By 288, his period as governor now over, Constantius had been made [[praetorian prefect]] in the west under Maximian.<ref name="DiMaio, Constantine I Chlorus"/> Throughout 287 and into 288, Constantius, under the command of Maximian, was involved in a war against the [[Alamanni]], carrying out attacks on the territory of the [[barbarian]] tribes across the [[Rhine]] and [[Danube]] rivers.<ref name="Southern, pg. 142">Southern, p. 142</ref> To consolidate the ties between himself and Emperor Maximian, Constantius married the emperor's daughter, [[Flavia Maximiana Theodora|Theodora]].<ref name="Potter, pg. 288"/>