Ordovices

[2] In 1879 the pioneering English geologist Charles Lapworth named the Ordovician geological period after the Ordovices because the rocks he was studying were found in the tribe's former territories in North Wales.

[3] The boundaries of the tribal territory are also unknown; they have been taken to extend through modern Powys into what is now the English Midlands, or alternatively to be limited to the land north of the rivers Dyfi and Dee.

The initial resistance was mainly organised by the Celtic leader Caratacus, exiled in their lands after the defeat of his tribe in the Battle of the Medway.

According to Tacitus, "He collected a force of veterans and a small body of auxiliaries; then as the Ordovices would not venture to descend into the plain, he put himself in front of the ranks to inspire all with the same courage against a common danger, and led his troops up a hill.

The location of this battle is unknown but the hill-fort Dinas Dinorwig encloses a hectare of land about 3 km from the Menai Strait.