I think that this thread is awfully narrow-minded and lacks independence. There's not a single alternative view here, so I'll start.
I believe the song is written about Napoleon Bonaparte's lifetime. I suspected it when I first heard the song, with lots of references to the French Revolution and the Christian references.
The first stanza sounds like Napoleon reminiscing while living out his capture and exile by the British following his magnificent fall from power.
The second stanza, with the idea of Napoleon as subject, they speak of Louis XVI's execution and Napoleon's takeover.
The third stanza discusses Napoleon's peak of power, holding the key to everything as emperor of his Empire. The following lines then go on to describe how Napoleon's Marshals mutinied him at the end of the War of the Sixth Coalition, resulting in his exile and effectively shutting him out of everything he used to own.
The chorus is most certainly a Christian reference, but is in this case a comparison for Napoleon's figurative crucifixion. He did a lot of incredibly beneficial things as ruler (namely, restoring order out of the Revolution and creating the Napoleonic Code), but in the end, people feared his influence far too much and deposed him from a seat of power. Perhaps the chorus is Napoleon reflecting on this thought that he is a Christ-like figure and imagines his own judgment at the end of his days similar to that of Christ’s end (He was a baptized and practicing Catholic), the other European nations like Rome persecuting Christ and his followers. Napoleon’s missionaries as his mirror, sword, and shield would most likely be the remnants of his armies and other supportive revolutionaries. (There was a long period following the reestablishment of the French monarchy that revolutionaries of Napoleon’s republic were still being rooted out, even going so far as rebuilding the city so rebels would no longer be able to barricade themselves in the narrow streets.) These missionaries could do a number of things: testify to his memory, speak of liberty, or advocate a new republic. Take your pick, it all happened.
The second portion of the chorus describes how power is the downfall of such prominent figures. Both Christ and Napoleon had rumors and sinister plots circulating behind their backs at the peak of their lifetime. “Once you go there” is likely saying that when one reaches the height of power, favor can turn to fear and dissent, regardless of how much everyone may seem to like you or how sterling your reputation may be.
Stanza four discusses Napoleon’s swift rise to power through the revolution, which was incredibly violent after Louis XVI was executed. Napoleon brought order to the chaos and many were at his feet for it. But it was that swift rise to power that would bring about his end.
The fifth stanza describes the Royalist revolutionaries that reinstated the monarchy and then had him shut out. For one who restored order out of a revolution, he was being revolted against now. The lonely string for the puppet (king) is the will of society, which all rulers are at the mercy of. Oh who would ever want to be king?
And then the chorus repeats, but with a new second line for the chorus’ second stanza. CRUCIAL MISTAKE on the original poster’s fault is that the “will” should be a “won’t.” Therefore, this song CANNOT be about Christ because I’m fairly certain that God (Christ=God on Earth) can let himself into Heaven again (and on that note, there weren’t any windows to break—4th stanza-- in Jerusalem during Christ’s time). This particular portion is Napoleon doubting that he will even be admitted into Heaven for his dissimilarities with Christ (sins: pride, greed, lying, believing himself to be like God), effectively separating the two views of the prominent figures. For his sins, he may not be rewarded in the same way.
Just an alternative little something to discuss…