River Thames to the strong current of the river, but also other river users. Organised swimming events take place at various points generally upstream of Hampton Court, including Windsor, Marlow and Henley. In 2011 comedian David Walliams swam the from Lechlade to Westminster Bridge and raised over £1 million for charity. In non-tidal stretches swimming was, and still is, a leisure and fitness activity among experienced swimmers where safe, deeper outer channels are used in times of low stream. A Thames meander is a long-distance journey over all or part of the Thames by running, swimming or using any of the above
River Thames banks of the Brent but have been buried under centuries of silt. Some of the earliest written references to the Thames () occur in Julius Caesar's account of his second expedition to Britain in 54 BC, when the Thames presented a major obstacle and he encountered the Iron Age Belgic tribes the Catuvellauni and the Atrebates along the river. The confluence of the Thames and Cherwell was the site of early settlements and the River Cherwell marked the boundary between the Dobunni tribe to the west and the Catuvellauni tribe to the east (these were pre-Roman Celtic tribes). In the