Epigraphs are like little appetizers to the great entrée of a story. They illuminate important aspects of the story, and they get us headed in the right direction.
EPIGRAPH: We see not one, not two, not three, but no less than four epigraphs. Check them out.
What's up with the epigraph?
Since this is actually four separate novels brought together as one, there are four epigraphs.
The Once and Future King
She is not any common earth
Water or wood or air.
But Merlin's Isle of Gramarye
Where you and I will fare.
This is from a Rudyard Kipling poem called "Puck's Song," part of a larger work called "Puck of Pook's Hill," published in 1906.
It's a fantasy about two children being told fantastical stories by various people who have been stolen out of history by Puck. And this is totally fitting when we consider Merlyn has been sort of stolen out of history, living backwards through time. The poem also references "Gramarye," where White likely got the name he uses for Arthur's realm.
The Queen of Air and Darkness
When shall I be dead and rid
Of the wrong my father did?
How long, how long, till spade and hearse
Put to sleep my mother's curse?
White drops in a snippet from a poem by A.E. Housman called "The Welsh Marches." You should notice right away that it encapsulates and foreshadows one of the major themes of this book: how your family legacy can have horrible repercussions that you have zero control over.
The Ill-Made Knight
"Nay," said Sir Lancelot "...for once shamed may never be recovered."
It's totally fitting for White to use this quotation from Malory's Morte d'Arthur (Book 5, Chapter 7, to be exact). Even though Lancelot is here speaking of shame in battle, it also applies to shame in general, and the biggie in this book is having the secret of Lancelot and Guenever's affair acknowledged openly by the Court—and by Arthur.
This is also a huge aspect of Lancelot's tragic flaw: he is unable to remain pure, so cannot perform miracles to the extent he wishes (he barely heals Sir Urre).
The Candle in the Wind
He thought a little and said:
"I have found the Zoological Gardens of service to many of my patients. I should prescribe for Mr. Pontifex a course of the larger mammals. Don't let him think he is taking them medicinally..."
This is an excerpt from Samuel Butler's 1903 novel, The Way of All Flesh. The fact that the speaker is sending Mr. Pontifex to the zoo to learn something reflects White's use of animals to teach lessons to Arthur. We are reminded of these lessons again at the very end of the book, cementing their importance to the entire story arc.