Your and Lighter's posts above convinced me that the Prince of Gehenna was indeed intended to be Metternich, and Gehenna is what I would sing if I could (someone else in my regular singaround does the song, so it's off limits for the foreseeable). 'Vienna' and 'Gehenna' are close rhymes and a contemporary would of course have twigged the connection immediately. Obviously the writer was an ardent Bonapartist. However, bringing Bonaparte's young son into the same line is still a puzzle for me.

Gehenna was, and is, a real place - a small valley in east Jerusalem which is easily found on Google Earth. It seems that in biblical times there was a community of Phoenicians in the area who practiced their reprehensible custom of child sacrifice by fire here. It is mentioned in several places in the bible. The aerial view seems to show an industrial estate - a blandly prosaic fate for a place of revolting horror.

I believe the valley is called Hinnom nowadays. Nearby is a road called Gihon.

Ain't the Interweb wonderful.