prehistoric beliefs and practices that at times seem directed toward one aspect of the supreme sky god and at other times appear to be concerned with a separate thunder deity. Although beginning perhaps much earlier, the thunder cult became especially prominent in western Europe during the Neolithic Period. In the cult, the ax appears to have been regarded as the symbol of the thunderbolt hurled by the sky god. Numerous representations of the ax have been discovered on painted rocks and the walls of Neolithic tombs; in addition, both large and small stone and clay axes with cuplike borings in them have been found, the smaller ones having been used as charms or votive objects.