Foil
Character Role Analysis
Queen of Underland / King Caspian
This is a bad ruler/good ruler issue. It's clear that Caspian has ruled well during his lifetime—we can see that he is beloved by his subjects, the castle looks to be in good condition, and we're told about his exploits to shore up the realm. It's true that Caspian has had poor personal luck, what with his family being lost and everything, but that's more personal than political, if you will.
The Queen of Underland, however, has enslaved the entire race of gnomes from Bism to do her dirty work and can only keep her realm in one piece by spells and enchantments. She's a tyrant, and it's clear that no one will shed a tear or make any effort on her behalf once she's been vanquished—unlike the extraordinary lengths that Aslan goes through for Caspian. In terms of posterity, Caspian's legacy is secured through the return of his good son, Rilian, while the Queen's realm, on the other hand, collapses into oblivion the moment she is killed.