The British Prime Minister recently chose the Cornish name Endellion as the middle name for his new daughter. The baby was premature, and born while the family was on holiday in Cornwall, and Endellion was chosen because the family regularly holidayed at the little village of St Endellion, so strictly speaking the name belongs with the growing trend to use place names (such as Dakota, Savannah) as first names. However, it is also a traditional Cornish name.
But first a bit of background. Cornwall is a popular holiday place because of its unspoilt beauty. Its unspoilt beauty comes from the fact that its position at the extreme south west of England makes it isolated. This isolation protected it in the past, and led to the preservation of a uniquely Cornish culture.
1500 years ago, when the rest of England was being taken over by the Anglo-Saxons, Cornwall remained independent and retained its own language, descended from the language of the ancient British and closely related to Welsh, into the 18th century. This language is the source of many of the specially Cornish names, while the distinctive West-Country way of pronouncing English has been another source.