Here in Wales, the authorities have the annoying habit of pointlessly wasting our money by changing signs so that they give place-names in Welsh and English, even here in South Pembrokeshire, known as Little England Beyond Wales, which has not been Welsh speaking for about 800 years. Here many of the place-names are English or Norse in origin, so that the Welsh names given appear to be either modern translations or simply renderings of the same name so that it sounds more "Welsh". Is there any way I can find out if a place name is an ancient Welsh name or some modern confection brought about by the need to follow political diktat? How does one find out the earliest citation of a place name?
