Power-ful song
Obviously this song really resonates with people, which is why it is so popular and why so many people want to delve into the meaning. It may be based on some real king, but the circumstances of rise and fall, corruption and abuse of power, being manipulated by others, regret for past wrongdoing, are all within the scope of anyone who's been in a position of power. We can relate to it, because even though we may have never really "ruled the world", most of us have had times when we felt like we did, even if only for a moment.
I hear a lot of disagreement about the line "I know St. Peter won't/will call my name. " I thougt it was "will" until I read lyrics on Coldplay's site. Now I listen, and yeah, I hear "won't". Does it change to "will" at the end? hard to tell. I thought about how it would change the meaning of the song. I don't think it really does, because the point of this line is just that the king is thinking of his death. Whether or not he believes he should be forgiven, he feels uncertain about how he should be judged, "for some reason I can't explain". That's something we can personally relate to, and why I think people hear what they want in that line of the song.