"
ringing
Roman Cavalry choirs are singing
Be my mirror, my sword and shield
My missionaries in a foreign field
For some reason I can't
Verse talks about battle coming along "be my mirror my sword and shield is a metaphor for asking for help" you need a shield and sword the mirror shows the truth he isn't so strong now! Head on a silver plate he has been taken over. Saint peter is then mentioned who according to Christians meets you in heaven at the pearly gates.
In Conclusion it asks who is the leader anyway and does it matter its a song to be seen as a protest.