Regni

The Regni, Regini, or Regnenses were a tribe based largely on Sussex and which occupied modern West Sussex, East Sussex, south-west Kent, eastern Surrey, and the eastern edges of Hampshire. Their tribal centre was at Noviomagus Reginorum (Chichester in West Sussex), close to Trisantona Fluvius (the River Arun) which joined the English Channel at Littlehampton, a little way to the east of Noviomagus Reginorum. The tribe was bordered to the west by the Belgae, to the north by the Atrebates, and to the east by the Cantiaci, while much of their northern border was filled by the vast and near-impenetrable Weald Forest. Nevertheless, they were thinly scattered on either side of the Weald, and there were safe paths through the forest.

The Regni were probably one of the most Romanised of British tribes. They had established trading links with Rome, including a Roman trading post dating and limited Roman presence before the Roman invasion of AD 43. The Romans' extensive use of Chichester Harbour in the territory of the Regni shortly after AD 43 suggests that that the Regni's pro-Roman links provided the Romans with a route to supply the Roman legions campaigning in the south-west of Britain.