Although it is not quite the longest river in Britain (the Severn river is 10 km longer), the Thames is by far the best known. This is perhaps of little surprise given that it flows through the heart of London, the capital city, and has played a central role in British history for some 2,000 years. From the Roman invasions of 43 CE to the turn of the millennium in 2000 the Thames has witnessed some of the most famous events in British history. These include the signing of the Magna Carta in 1215, the gunpowder plot of 1605 and the Great Fire of London in 1666.