Which river flows through the cities of London, Oxford, and Reading?

The River Thames flows through Oxford, Reading, and London before reaching the North Sea.

The Thames is the longest river entirely in England, running for about 215 miles from its source near Kemble in Gloucestershire to the Thames Estuary. It passes through or beside many historic settlements, including Oxford, Reading, Windsor, and London. In its upper reaches it is sometimes called the Isis, particularly around Oxford, but “Thames” is the standard name for the river as a whole.

The river has shaped English history, transport, and commerce for centuries. London’s growth was closely tied to its navigable waterway and port. The Thames also hosted the 1851 Great Exhibition near Hyde Park and remains central to events such as the Oxford-Cambridge Boat Race. The tidal section through London is affected by the North Sea, which is why the Thames Barrier was built and opened in 1982 to help protect the capital from storm surges.