The River Thames which flows through the centre of London is probably as famous as any other landmark in the capital. But, how much else do we know about this historic river? I say historic because it has existed for thousands of years. Over 2,000 years ago, the Romans built a port here when London was known as Londinium. But, how much do we know about the river outside of London?
It joins the North Sea about 40 miles to the east of London, not far from the new city of Southend. So, that it where it ends. But, where does it start? This is not as simple as it might at first appear. There are a couple of candidates but the one which seems to be the favoured site is a place called Thames Head (not much imagination there). It is about a mile north of the village of Kemble, in the county of Gloucestershire. To mark this spot, there is a stone inscribed to tell you that you are at the head of the Thames.

The total length of the river is 215 miles and it is the longest river to flow just in England. The River Severn is longer but it shares it with Wales. Now we come to the problem of whether the Thames is the Thames for the whole of its length? The name would seem to change as it passes through different areas. For example, the people of Oxford have named it the Isis. They go on to say that it does not become the Thames until it reaches Dorchester-on-Thames. It is at this point that the Thames is joined by another river. This one confusingly is called the Thame. Yes, just one letter missing.
On top of this, there are some who say that at this point of the two rivers joining, the name becomes the Thamesis or the Thamesisis. This is really becoming confusing, but local legends and history often throw up these anomalies. My personal view is that those who wish to call the Thames the Thames for the whole of its length, should have their way and for those in Oxford, they can stay with calling it the Isis.