The origin of the name 'Sirhowy' has been the subject of much conjecture over many years.

One theory gives the origin as being directly from the Welsh ' sorwy ' meaning ' wild or angry water '

Another version dates back to Norman times when a great battle was fought in the area.
The Welsh forces were exhausted and their leader attempted to rally them for one last effort against the opposing army.

When he asked ' Who is ready to stand and fight again? '
To a man, they replied in Welsh: ' Syr wy i '   translated as :  ' I am, Sir '
The battle was later won and the nearby river was named ' Syr-wy-i ' thereafter.

A variation on this story gives the Welsh general's name as Sir Howell or Sir Howy, as he was known by his men, and the river was named in his honour.