Riding. The Brigantes controlled territory which later became all of Northern England and more territory than most Celtic tribes on the isle of Great Britain. Six of the nine Brigantian poleis described by Claudius Ptolemaeus in the Geographia fall within the historic county. The Parisi, who controlled the area that would become the East Riding of Yorkshire, might have been related to the Parisii of Lutetia Parisiorum, Gaul (known today as Paris, France). Their capital was at Petuaria, close to the Humber Estuary. 43–400s: Britannia Inferior Although the Roman conquest of Britain began in 43 AD, the Brigantes remained in control of their kingdom as a client state of Rome for an extended period, reigned over by the Brigantian monarchs Cartimandua and her husband Venutius. The capital was between the north and west ridings Isurium Brigantum (near Aldborough) civitas under Roman rule. Initially, this situation suited both the Romans and the Brigantes, who were known as the most militant tribe in Britain. Queen Cartimandua left her husband Venutius for his armour bearer, Vellocatus, setting off a chain of events which changed control of the region. Cartimandua, due to her good relationship with the Romans, was able to keep control of the kingdom; however, her former husband staged rebellions against her and her Roman allies. At the second attempt, Venutius seized the kingdom, but the Romans, under general Petillius Cerialis, conquered the Brigantes in 71 AD. The fortified city of Eboracum (now known as York) was named as capital of Britannia Inferior and joint capital of all Roman Britain. The emperor Septimius Severus ruled the Roman Empire from Eboracum for the two years before his death. Another emperor, Constantius Chlorus, died in Eboracum during a visit in 306 AD. Thereafter his son Constantine the Great, who became renowned for his acceptance of Christianity, was proclaimed emperor in the city. In the early 5th century, the Roman rule ceased with the withdrawal of the last active Roman troops. By this stage, the Western Empire was in intermittent decline. 500s–1000s: Germanic landings 500s–800s: Celtic-Anglo kingdoms of Ebrauc, Elmet, Deira and Northumbria After the Romans left, small Celtic kingdoms arose in the region, including kingdoms of Deira to the east (domain of a settlements near Malton on Derwent), Ebrauc (domain of York) around the north and Elmet to the west. The latter two were successors of land south-west and north-east of the former Brigantia