The Ballad of the White Horse (Version 3) by G. K. Chesterton

This epic poem is about Alfred the Great's defense of Christian England against the pagan Viking invaders. The decisive battle is fought in sight of a white horse mark made on a hill, after which the poem is named. As the white horse mark must be continually maintained by weeding to be clearly seen, Chesterton sees it as a symbol of the continual struggle to maintain the Christian culture and values for which Alfred the Great fought. - Summary by Robin Lamb