IV.

History

Interesting archaeological discoveries have been made in the Thames valley, including fossils of seashells and a human skull of the Palaeolithic period. The Roman invading force (see Roman Britain) commanded by Julius Caesar penetrated to the Thames valley in 55 bc, and Caesar named the river Tamesis. The armies of Claudius's invasion in ad 43 are thought to have first forded, and perhaps bridged, the river in the area of today's Westminster Bridge.

At that time the river in this stretch was shallower and approximately twice its current width, with low-lying marshy ground on either side. When the Romans came to develop the settlement as a port and city, however, they chose a site on higher ground with deeper water, about 1.6 km (1 mi) further downstream, the site of today’s London Bridge and, on the north bank, the City of London. From the late 8th century onward the Thames valley was an important route for invading Vikings, penetrating far inland by ship. In the Middle Ages the valley was prosperous, with many famous religious houses and several large towns, including Oxford, Reading, and Windsor.