Editing Constantius Chlorus (section)

===Elevation as Caesar===
[[File:Argenteus-Constantius I-antioch RIC 033a.jpg|250px|thumb|On the reverse of this [[argenteus]] struck in [[Antioch]] under Constantius Chlorus, the [[tetrarchy|tetrarchs]] are sacrificing to celebrate a victory against the [[Sarmatia]]ns.]]
By 293, [[Diocletian]], conscious of the ambitions of his co-emperor for his new son-in-law, allowed Maximian to promote Constantius in a new power sharing arrangement known as the [[Tetrarchy]]. The eastern and western provinces would each be ruled by an [[Augustus (honorific)|''augustus'']], supported by a [[Caesar (title)|''caesar'']]. Both ''caesares'' had the right of succession once the ruling ''augustus'' died.<ref name="Southern, pg. 145">Southern, p. 145</ref>

At [[Mediolanum]] ([[Milan]]) on 1 March 293, Constantius was formally appointed as Maximian's ''caesar''.<ref>Birley, p. 382</ref> He adopted Diocletian's ''[[Roman naming conventions|nomen]]'' (family name) "Valerius", and, being equated with Maximian, also took on "Herculius".<ref name="Southern, pg. 147">Southern, p. 147</ref>  His given command consisted of [[Gaul]], [[Roman Britain|Britannia]] and possibly [[Hispania]]. [[Diocletian]], the eastern ''augustus'', in order to keep the balance of power in the ''imperium'',<ref name="Southern, pg. 145">Southern, p. 145</ref> elevated [[Galerius]] as his ''caesar'', possibly on 21 May 293 at [[Philippopolis (Thrace)|Philippopolis]] ([[Plovdiv]]).<ref name="Potter, pg. 288">Potter, p. 288</ref> Constantius was the more senior of the two ''caesares'', and on official documents he always took precedence, being mentioned before Galerius.<ref name="Southern, pg. 147">Southern, p. 147</ref> Constantius's capital was to be located at [[Augusta Treverorum]] ([[Trier]]).<ref>{{Citation|last1=Woolf|first1=Greg|title=The Cambridge Illustrated History of the Roman World|year=2003|editor-last=Nicholson|editor-first=Oliver|publisher=Cambridge University Press|url=https://books.google.com/books?id=qO54sAEvDL4C&pg=PA224|isbn=9780521827751|page=224}}</ref>

Constantius's first task on becoming ''caesar'' was to deal with the [[Roman usurper]] [[Carausius]] who had declared himself emperor in Britannia and northern Gaul in 286.<ref name="Potter, pg. 288"/>  In late 293, Constantius defeated the forces of Carausius in Gaul, capturing Bononia ([[Boulogne-sur-Mer]]).<ref>Birley, p. 385</ref> Carausius was then assassinated by his ''[[rationalis]]'' (finance officer) [[Allectus]], who assumed command of the British provinces until his death in 296.<ref>{{cite encyclopedia | last = Schmitz | first = Leonhard | author-link = Leonhard Schmitz | title = Allectus | editor = William Smith | editor-link = William Smith (lexicographer) | encyclopedia = [[Dictionary of Greek and Roman Biography and Mythology]] | volume = 1 | pages = 132 | publisher = [[Little, Brown and Company]] | location = Boston | year = 1867 | url = http://quod.lib.umich.edu/cgi/t/text/pageviewer-idx?c=moa;cc=moa;idno=acl3129.0001.001;q1=demosthenes;size=l;frm=frameset;seq=147}}</ref>

Constantius spent the next two years neutralising the threat of the [[Franks]] who were the allies of Allectus,<ref name="Southern, pg. 149">Southern, pg. 149</ref> as northern Gaul remained under the control of the British usurper until at least 295.<ref>Birley, p. 387</ref> He also battled against the [[Alamanni]], achieving some victories at the mouth of the [[Rhine]] in 295.<ref>Birley, pp. 385–386</ref> Administrative concerns meant he made at least one trip to Italy during this time as well.<ref name="Southern, pg. 149"/> Only when he felt ready (and only when Maximian finally came to relieve him at the Rhine frontier)<ref name="Southern, pg. 150">Southern, p. 150</ref> did he assemble two invasion fleets with the intent of crossing the [[English Channel]]. The first was entrusted to [[Julius Asclepiodotus]], Constantius's long-serving [[Praetorian prefect]], who sailed from the mouth of the [[Seine]], while the other, under the command of Constantius himself, was launched from his base at Bononia.<ref>Birley, p. 388</ref> The fleet under Asclepiodotus landed near the [[Isle of Wight]], and his army encountered the forces of Allectus, resulting in the defeat and death of the usurper.<ref>[[Aurelius Victor]], ''Liber de Caesaribus'', [http://www.thelatinlibrary.com/victor.caes.html#39 39]</ref> Constantius in the meantime occupied [[Londinium]] ([[London]]),<ref>Potter, p. 292</ref> saving the city from an attack by [[Franks|Frankish]] mercenaries who were now roaming the province without a paymaster. Constantius massacred all of them.<ref name="Southern, pg. 150">Southern, p. 150</ref>
[[File:Bust of Constantius Chlorus - Altes Museum - Berlin - Germany 2017.jpg|alt=Portrait head of Constantius Chlorus.|thumb|Portrait head of Tetrarch, most likely Constantius Chlorus.<ref>[http://laststatues.classics.ox.ac.uk/database/discussion.php?id=1227 http://laststatues.classics.ox.ac.uk, LSA-855 ((K. Dahmen, M. Maischberger, C. Blümel)]</ref>]]
Constantius remained in Britannia for a few months, replaced most of Allectus's officers, and the British provinces were probably at this time subdivided along the lines of Diocletian's other administrative reforms of the Empire.<ref>Birley, p. 393</ref> The result was the division of [[Britannia Superior]] into [[Maxima Caesariensis]] and [[Britannia Prima]], while [[Flavia Caesariensis]] and [[Britannia Secunda]] were carved out of [[Britannia Inferior]]. He also restored [[Hadrian's Wall]] and its forts.<ref>Birley, p. 405</ref>

Later in 298, Constantius fought in the [[Battle of Lingones]] ([[Langres]]) against the [[Alemanni]]. He was shut up in the city, but was relieved by his army after six hours and defeated the enemy.<ref>Eutropius, ''Breviarum'' {{usurped|1=[https://web.archive.org/web/20031222152525/http://www.forumromanum.org/literature/eutropius/trans9.html#23 9.23]}}</ref> He [[Battle of Vindonissa|defeated them again at Vindonissa]]<ref>[http://www.unrv.com/military/battles-of-the-third-century.php UNRV History: Battle of the Third Century AD]</ref> thereby strengthening the defences of the [[Rhine]] frontier. In 300, he fought against the [[Franks]] on the Rhine frontier,<ref name="Southern, pg. 152">Southern, pg. 152</ref> and as part of his overall strategy to buttress the frontier, Constantius settled the Franks in the deserted parts of [[Gaul]] to repopulate the devastated areas.<ref>Birley, p. 373</ref>  Nevertheless, over the next three years the Rhine frontier continued to occupy Constantius's attention.<ref name="Southern, pg. 152"/>

From 303 – the beginning of the [[Diocletianic Persecution]] – Constantius began to enforce the imperial edicts dealing with the [[Persecution of Christians in the Roman Empire|persecution of Christians]], which ordered the destruction of [[Church (building)|churches]].<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> The campaign was avidly pursued by [[Galerius]], who noticed that Constantius was well-disposed towards the [[Christians]], and who saw it as a method of advancing his career prospects with the aging Diocletian.<ref>Potter, p. 338</ref> Of the four Tetrarchs, Constantius made the least effort to implement the decrees in the western provinces that were under his direct authority,<ref>Potter, p. 339; Southern, p. 168</ref> limiting himself to knocking down a handful of churches.<ref name="DiMaio, Constantine I Chlorus">DiMaio, ''Constantine I Chlorus''</ref> [[Eusebius]] denied that Constantius destroyed Christian buildings, but [[Lactantius]] records that he did.<ref name=":0" />