AE Follis (AE1), A.D. 305-306, Trier, 27mm, 10.29g, 180°, RIC VI 642a; scarce.
Obv: IMP CONSTANTIVS P F AVG. Laureate and cuirassed bust right.
Rev: GENIO POPVLI ROMANI, Genius standing left, holding patera and cornucopiae; SF in field, PTR in ex.
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Constantius Chlorus, was Roman Emperor from 305 to 306. He was the father of Constantine the Great and founder of the Constantinian dynasty. Before 305, as Caesar he defeated the usurper Allectus in Britain and campaigned extensively along the Rhine frontier, defeating the Alamanni and Franks.

Diocletian and Maximian stepped down as co-emperors on May 1, 305, possibly due to Diocletian's declining health. Before the assembled armies at Milan, Maximian removed his purple cloak and handed it to Severus, the new Caesar, and proclaimed Constantius as Augustus. The same scene played out at Nicomedia under the authority of Diocletian. Constantius ruled the western provinces, while Galerius took the eastern provinces.

In 305 Constantius crossed over into Britain, travelled to the far north of the island and launched a military expedition against the Picts, claiming a victory against them and the title Britannicus Maximus II. After retiring to Eboracum (York) for the winter, Constantius had planned to continue the campaign, but on 25 July 306, Constantius died. As he was dying, Constantius recommended his son to the army as his successor; consequently Constantine was declared emperor by the legions at York.