The reference is to Octavian, the Emperor Augustus, who, at least in theory, brought peace to the Roman Empire; hence ‘mundus pacis’, the inscription on the orb he holds. The birth of a child from heaven is mentioned in Virgil’s fourth Eclogue associated with Augustus, and was taken by Christians as a prophecy of the birth of Christ in the time of Augustus.
[Version 0.05: May 2008]