First person to swim the length of the River Thames

The first person to swim the length of the River Thames, the UK's second-longest river, is Lewis Pugh (UK), who navigated the 327-kilometre (203-mile) waterway from its source near Kemble in Gloucestershire to its terminus off Southend-on-Sea, Essex, between 17 July and 6 August 2006.

Extreme swimmer, environmental activist and maritime lawyer Lewis Pugh has performed a number of record-breaking swims in order to draw attention to climate change, over-fishing and pollution, and to campaign for greater protection of the oceans. In 2013, he was elected the UN's first Patron of the Oceans.

Owing to a drought in the summer of 2006, fittingly demonstrating the impact of rising temperatures, Pugh had to run the first 40 km (25 mi) from the source until he reached water that was deep enough to swim in near the town of Lechlade, Gloucestershire.

Pugh initially intended to complete the swim in 10 days but in all it took 21 days, with a total swimming time of 81 hours 49 minutes. The journey was harder going than expected as there was very little current owing to the low water levels; this also meant the water was more muddy and polluted than normal, which resulted in Pugh falling ill several times en route.

On reaching London, Pugh was invited by the then Prime Minister Tony Blair to stop by No.10 Downing Street in order to present a letter that urged carbon emissions to be reduced in the UK by 2010.