Silures

The Silures were a powerful and warlike tribe of ancient Britain, occupying approximately the counties of Monmouthshire, Breconshire and Glamorganshire of present day South Wales; and possibly Gloucestershire and Herefordshire of present day England. They were bordered to the north by the Ordovices; to the east by the Dobunni; and to the west by the Demetae.

Read more about Silures:  Origins, Fierce Resistance To Roman Forces, Romanization, The Term "Silurian"