The Statistical Account of 1793 is quite sure that this stone commemorates where the leader of the Danes, Camus, was killed. The writer called upon George Buchanan’s history of Scotland to back him up. That was written in the late 16th century. I decided to look it up and the relevant chapter, about Malcolm II (the Eighty Third king of Scotland, no less) is really quite grippingly written, different armies dashing about, Malcolm being Wounded in the Head, people being discouraged and crest-fallen, but then things turning about and the Danes “flying to the Mountains towards Murray, before [Camus] had gone two miles, was overtaken by the Pursuers, and he and all his Men cut off. There are monuments extant of this Victory, in an Obeliske, and a Neighbouring Village, which as yet retains the Memorable Name of Camus.” There’s some ghastly stuff about Malcolm’s eventual end as well, but I will resist quoting it.
I’m not convinced though, that it particularly refers to this location in Buchanan’s book. But the story is no doubt the same whichever Camus stone you’re at (and there are / were a number of them).
Camus is a bad as Macbeth he seemed to die everywhere. (Macbeth definitely died near Lumphanan tho.)