The River Severn surges south from its birth place in Wales to meet the sea at the Bristol Channel.It is not widely known that the part of England west of the Severn spoke Welsh until the Eighteenth century. Furthermore, a version of Welsh was spoken in Derbyshire [North Midlands, quite hilly] until the twelfth century. There is place name evidence that Lancashire spoke a mixture of Welsh and English in the late first millennium. Ince is a Lancashire town whose name drives from the Celtic inis,meaning an island.The town had been constructed on an island in swampland.In the east of the Manchester conurbation I used to walk to work up a steep street called Penny Meadow, whose name is a combination of the English word meadow and the Welsh y pen, meaning the high [pen y meadow.] There are six living Celtic tongues, three of which are Brythonic [derived from Britain]and three Gaelic [of Irish origin.] A fourth Brythonic tongue is known,but not spoken [more later.] Of the Brythonic tongues Welsh and Cornish are spoken in Britain, but Breton is spoken in Brittany, France.
Welsh is spoken only in Wales, and is very much found most on the west and in the hills. While it is the joint official language of Wales, not everyone is keen on it. The Welsh language comes in two variants, spoken in North and South Wales respectively. The official language of Wales is the southern variety.
Cornish was a language that died out in the 1870s but was revived by enthusiasts. A few people use it in Cornwall, England's most southwesterly county, which has a small nationalist movement, its own tartan based on Scottish models and its own flag. Cornwall was a Celtic kingdom absorbed into Saxon Wessex in the tenth century. While it is in England many Cornish do not call themselves English as they like to regard themselves as having a distinct identity.
"Yan, tan, tethera...." was the way in which Cumbrian shepherds in England's most north-westerly county used to count to three.They were counting in Cumbric, a long extinct, unrecorded Brythonic language of Northern England spoken when the North was known as Hen Ogledd, the Old North, before the Angles' expansion.Several different Cumbric counting systems are known, so Cumbric must have been a fragmented system of local dialects.Sadly,no written records remain, and St Bede, writing in the eighth century did not see Cumbric as sufficiently distinct from Welsh to merit mentioning.
No written texts in Pictish, the pre-Gaelic language of much of Scotland, survive and whether it was a Celtic tongue or a relict pre-Celtic language is unknown. more recently some scholars have suggested that it was a Germanic language related to Norse. Certainly in many parts of Scotland Norn was spoken. We have thought it introduced by the Vikings, but if the Norse tongue was related to Pictish anyway the two languages would easily meld.North-Eastern Scotland, where the Picts were prevalent, never spoke Gaelic, but a version of English, so it is unlikely that Pictish was a form of Celtic.
The only relics of Norn are found on lonely Fair Isle between Orkney and Shetland where some Norse seabird names survive.