It should also be noted that the name for rocking stones could be a modified form of the Danish word "logre," which means 'to wag the tail,' and this suggests possible Norse origin. Danes in particular established a kingdom in Great Britain before 1000 AD, Norway maintained nominal control over the Hebrides in northern Scotland until the late Middle Ages, and Vikings frequently raided along the British coastal areas between 800 and 1000 AD Thus, a Norse origin for the word Logan, while speculative, cannot be ruled out.