 Events came to a head when the emperor Septimius Severus, intending to attack the Caledones, established himself at York in 209 AD, designating it the capital of the northern region (although this region, Britannia Inferior, may not have been formally established until after his death in 211).He also strengthened Hadrian's Wall and he may have established the "civitas" (a form of local government) of the Carvetii with its centre at Carlisle (Luguvalium).The settlement of Severus, carried forward diplomatically by his son Caracalla, led to a period of relative peace in the north, which may have lasted for most of the 3rd-century (we are severely hampered by the lack of sources concerning the northern frontier for most of the 3rd century, so this may be a false picture).