Maxima Caesariensis

At some point after the territory was retaken by Constantius Chlorus in AD 296, the Diocese of the Britains (with its vicar at Londinium) was formed and made a part of Prefecture of Gaul.

[5][6][7] The placement and capitals of these late British provinces are uncertain, although the Notitia Dignitatum lists the governor of Maxima (originally an equestrian praeses) as having been elevated to consular rank.

[8] Describing the metropolitan sees of the early British church established by SS Fagan and "Duvian", Gerald of Wales placed "Maximia" in Eboracum (York) and Londinium in Flavia,[9][10] saying the former was named for the emperor Maximus.

[9] William Camden followed him[2] and this placement was generally accepted after the appearance of Charles Bertram's highly-influential 1740s forgery The Description of Britain, which gave Maxima borders from the Humber and Mersey to Hadrian's Wall;[11] this work was debunked over the course of the mid-19th century.

[12] Birley has argued that Maxima and Flavia originally consisted of a single province, which received the name Britannia Caesariensis as a mark of favour for support against the rebel Allectus in 296.