Lyric discussion by fadetoflashes 

Cover art for The Infanta lyrics by Decemberists, The

This doesn't have any certain moral, it just describes the personages that would be present at such an event as a coronation. A baron, the Prince, a Moor, the King, etc. It's just that in the end, it hints that she is not biologically related to her parents, and was found in a cradle floating on the water. That suggests an air of foreigness, or mystery, about her.