Well, When the little kids find the skull Kaspar repeatedly says basically that they are from the Great Victory - He said that: It was the English, Kaspar cried, Who put the French to rout; SO he is saying that they fought (war) with one another. The skulls symbolize the great victory because he says: They said it was a shocking sight After the field was won; For many thousand bodies here Lay rotting in the sun; SO the bodies remained on the land where Kaspar and the kids are, and that is why at times they find skulls. The skulls symbolize the war that was won on their land.