Caratacus, whose tribe, the Catuvellauni, had been defeated in the first phase of the conquest, has reemerged as a leader of the Silures of south east Wales and Gloucestershire.

Their rising is controlled by a program of legionary fortress construction, driving Caratacus north into the lands of the Ordovices.

Ostorius manages to force him into an open conflict, after several years of guerrilla war.

Tacitus's Annals has Caratacus leading the Silures and Ordovices of Roman Wales against Ostorius, who in 50 finally manages to defeat Caratacus in a set-piece battle somewhere in Ordovician territory, capturing Caratacus' wife and daughter and receiving the surrender of his brother.

Caratacus himself escapes.

The site of the battle is unknown.

The hill fort on Caer Caradoc Hill in Shropshire is connected with the battle by virtue of its name.

Local legend places it at British Camp in the Malvern Hills.

However, the Severn, though visible from this location, is too distant to fit Tacitus's description of the site.

A position just west of Caersws, where the remains of earthworks still stand, has also been suggested, as has a location near Brampton Bryan.