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" by 7 January 306. After retiring to Eboracum (York) for the winter, Constantius had planned to continue the campaign, but on 25 July 306, he 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.