Whaley provides a summary of the history of linguistic influences on, plus a dictionary of, the place-names of the area covered by the Lake District National Park, plus entries for Kendal, Cockermouth and Penrith, Cumbria.
Evidence of this language is mostly visible in topographical features such as rivers (Kent, Eden, Ehen, Levens) and mountains (Blencathra, Helvellyn, Coniston Old Man).
In the first millennium AD the Brythonic spoken in north west England and southern Scotland developed into a separate strain called Cumbric.
Placenames with thwaite, which are commonplace in Cumbria, are also abundant in the southern counties of Hordaland, Rogaland, Agder and Telemark in Norway proper, and less in use elsewhere (Norwegian: tveit, tvedt).
Many mountains, rivers and valleys have Norse names, as attested by the abundance of the elements fell, -ay and dale (Mickledore, Scafell, Rothay, Duddon, Langsleddale, Allerdale).
Many town and villages also contain Norse elements (Keswick, Whitehaven, Ravenglass, Silloth, Ulverston, Ambleside) Common Old Norse elements[5] There are also a number of Danish influenced place names (Allonby, Thursby, Ousby, Milnthorpe), but the majority are situated along the Eden Valley and the north coast of the county, suggesting that they might have come across Stainmore around the 9th century AD.