 She asks that her father be given sovereignty over Britain, thus formalising the transfer of authority from Rome back to the Britons themselves.Historically Magnus Maximus was a Roman general who served in Britain in the late 4th century, launching his successful bid for imperial power from Britain in 383.This is the last date for any evidence of a Roman military presence in Wales, the western Pennines, and Deva (i.e., the entire non-Romanised region of Britain south of Hadrian's Wall).