In AD 43, the Roman Emperor Claudius sent a large Roman army to invade and conquer Britain, but why?

• There were two tribes in Britain who were always fighting to dominate the island: the Atrebates (pronounced at-ree-bart-ays) from Hampshire and the Catuvellauni (pronounced cat-oo-well-orn-ee) from Hertfordshire.
• The Atrebates were more Roman friendly. Their king, Verica, was thrown out of Britain by King Caradog of the Catuvellauni.
• Verica fled to Rome and asked Emperor Claudius to help him get his throne back.
• Britain had lots of rich minerals (especially gold, silver, tin, lead and iron) which the Romans wanted to mine.
• Britain was rich in farmland which the Romans wanted to tax and use to feed their armies.
• But the Romans thought Britain was at the end of the World. It was a place that no-one could conquer. 
• Claudius had a speech impediment and most people thought this was because he was stupid. He needed to show that he was a great emperor.
• There was a spare army just across the Channel in Gaul (France). The previous emperor had sent them there to invade Britain, but changed his mind.

The Romans conquered the South, Midlands and East of Britain quite quickly. Claudius even visited himself, with elephants! But it took forty years to take over the West and the North of Britain. Some of the British were pleased to have the Romans take over. Others, like Queen Boudica, fought against them.

The Romans eventually set up a new region of the Empire (or 'diocese') called Britannia, but they did not go into the mountainous region of Caledonia (Scotland) in the extreme north, where the Picts lived. They eventually set the border at Hadrian's Wall.