Cited from Wikipedia:
Numerous folktales are associated with the stones, including the tale reported in a rhyming version by William Camden in 1610, that a king was riding across the county with his army when he was accosted by a local witch called Mother Shipton, who said to him:
"Seven long strides thou shalt take, says she
And if Long Compton thou canst see,
King of England thou shalt be!"
His troops gathered in a circle to discuss the challenge and his knights muttered amongst themselves– but the king boldy took seven steps forward. Rising ground blocked his view of Long Compton in the valley and the witch cackled:
"As Long Compton thou canst not see, King of England thou shalt not be! Rise up stick and stand still stone, For King of England thou shalt be none; Thou and thy men hoar stones shall be, And I myself an elder tree!"
The king became the solitary King Stone, while nearby his soldiers formed a cromlech, or circle, called the King's Men. As the witch prepared to turn herself into an elder tree, she backtracked into four of the king's knights, who had lagged behind and were whispering plots against the king. She turned them to stone as well, and today they are called the Whispering Knights.The King Stone and the Whispering Knights are just across the border in Warwickshire.