“The cross began to turn up regularly on Christian monuments as well as small personal items fairly soon after Constantine’s prophetic heavenly vision and the momentous discovery of the relic of wood of the True Cross in Jerusalem. Because both of these events were associated with the imperial house, the emergence of the cross often has been seen at least initially as a symbol, employed by the emperor or his agents to be a sign of divine protection and patronage. Yet, almost immediately following its discovery, the cross began to distinguish itself from those imperial associations to become a devotional object in itself, without bearing any necessary or direct political or military meaning.”