When he first appears Aslan is a clear-cut character within a story. In The Lion, the Witch and the Wardrobe, he adopts a central role and plays out a part, albeit a fundamentally important one. He is Lewis’s attempt to ‘re-invent God’ for readers who have grown up in a culture from which God has either been removed or degraded. Aslan makes the four Pevensie children kings and queens, and banishes all traces of evil from his kingdom, before pulling the children back to Earth, their views invigorated.
By the time we reach the third book, The Voyage of the Dawn Treader, Aslan is more distant, appearing in other forms, such as a lamb and an albatross. He is even present but invisible, as the incident on the island of the Dufflepuds reveals. Lewis deepens our spiritual experience by making Aslan harder to find, and by changing his role. Faith - belief without seeing - becomes important. The character of the mouse Reepicheep, full of noble ideals, who is determined to find Aslan's Country, even if he has to swim to the end of the world to do so, is an embodiment of this. The Voyage of the Dawn Treader also introduces a non-believer, Eustace Clarence Scrubb. Eustace’s transformation from the dragon into which he is magically changed back into a boy, as Aslan peels away the layers of dragon skin, is a metaphor for conversion. This isn’t simply a Christian conversion, though, and the result is not merely ‘another Christian’: the whole point of the Chronicles is to ‘peel away’ the layers of a pervasive Ironic culture in order to show the reader a different way of looking at everything.
Aslan, being Lewis’s symbol for God, is not just a comforting icon, a wish-fulfilling fantasy ‘friend’ who could easily be accused of being a projection of humanity’s deepest needs, an allegory rather than a symbol. In The Silver Chair, when Jill and Eustace first get into Aslan's country, Jill accidentally pushes Eustace off a cliff, and Aslan therefore comes between her and a stream, warning Jill that he has eaten small girls before, ‘and boys, women and men, kings and emperors, cities and realms.’ He is ‘not a tame lion’. The fear and lack of predictability of the Lion mirrors the same qualities in the Christian God on one hand, and in the other reflects the qualities of a symbol, rather than an allegory or psychological projection.
These characteristics of receding into the background and being unpredictable blend together in the tale A Horse and His Boy. Instead of having his protagonists enter Narnia directly from a facsimile of our Ironic world, Lewis here plays with the geography of the world he has created. Such was the confidence demonstrated in the prior books, The Voyage of the Dawn Treader and The Silver Chair, that Lewis, now fully in command of his own creation, feels able with this story to make Narnia not the world as a whole but merely a country within it. Replacing our Ironic culture with all of its immediately recognisable woes is the nation of Calormen, drawing its imagery from Lewis’s ideas of an exotic and mediaeval Arabia.
The boy protagonist Shasta begins by overhearing a man he has never truly felt to be his father, and a Calormene aristocrat, bartering for him to be sold into slavery, a situation from which he escapes thanks to the aristocrat’s horse, which turns out to be a talking beast from Narnia. Narnia, and all that it represents to the horse Bree, becomes our goal through their quest to reach it. It is not long, though, before they encounter two lions who drive them into the company of another escaping Calormene, Aravis and her talking horse Hwin, something which at first appears to be a coincidence but is later revealed to be the action of Aslan, disguised as the lions.
This is the pattern of the tale: Aslan, disguised in various forms, directs the action of the story so that Shasta, on arriving in the Calormene capital Tashbaan, meets Susan and Edmund at the time when they were kings and queens of Narnia, and becomes entangled in the politics of the two kingdoms. Later, escaping from the city, he encounters Aslan again in the form of a cat, who protects him in the Tombs in the edge of the desert, and later still Aslan appears again as a wild lion, the fear of which gives the horses the final burst of speed they need to reach the Hermit of the Southern March and safety after fleeing across the desert.
All of this shows Aslan in an extended role: he became providential in The Voyage of the Dawn Treader, and this was expanded upon in The Silver Chair so that he didn’t just respond to the events of the plot but oversaw them explicitly. Now, in A Horse and His Boy, Lewis goes back in time to ‘re-boot’ Aslan as a providential force during the reign of the Pevensie children, clarifying for the reader what the Lion’s role has actually been all along.
This isn’t just a mechanical process though. In parallel to Aslan being shown as a force ‘behind the scenes all along’, he also becomes much more personal for the protagonist. In the first book, Lucy and Susan shared an intimacy with Aslan, playing with him and hugging him and so on after his resurrection, a spirit which Lewis struggled to recapture in the sequel, Prince Caspian; in the third book, Aslan appears to different characters at key points in their stories, correcting Caspian or transforming Eustace, but is not physically present to any great degree. This is then continued in The Silver Chair, in which Aslan, though present at the beginning and the end of the narrative, doesn’t appear directly to the characters throughout except in dreams. This trend towards the lack of a tangible presence appears to be persisting in A Horse and His Boy until Shasta detects a presence by his side as he makes his way through the darkness, feeling very sorry for himself:
What put a stop to all this was a sudden fright. Shasta discovered that someone or somebody was walking beside him. It was pitch dark and he could see nothing. And the Thing (or Person) was going so quietly that he could hardly hear any footfalls. What he could hear was breathing. His invisible companion seemed to breathe on a very large scale, and Shasta got the impression that it was a very large creature. And he had come to notice this breathing so gradually that he had really no idea how long it had been there. It was a horrible shock.
This presence invites Shasta to tell him his woes, and the boy does so, complaining in particular about how he was chased by a lion. It is at this point that the story, in which Aslan has apparently not made an appearance as yet, ‘flips’ - the godless and luckless reality that Shasta has endured is suddenly revealed to be quite different:
"I was the lion." And as Shasta gaped with open mouth and said nothing, the Voice continued. "I was the lion who forced you to join with Aravis. I was the cat who comforted you among the houses of the dead. I was the lion who drove the jackals from you while you slept. I was the lion who gave the Horses the new strength of fear for the last mile so that you should reach King Lune in time. And I was the lion you do not remember who pushed the boat in which you lay, a child near death, so that it came to shore where a man sat, wakeful at midnight, to receive you."
Shasta perceives Aslan as the guiding force behind every event of his life. In fact, Lewis here describes Aslan’s divine intervention in Shasta’s existence as more thorough than any other character in Narnia. The revelatory nature of that experience changes Shasta and acts for the reader as the ‘Dantean moment’, the moment when the world we thought we were in turns inside out.
Events play themselves out: the battle is won, people are restored to their rightful places and Narnia is saved. The key point of the story, the retrospective broadening of the role of Aslan in the world of Narnia, is successfully accomplished. Lewis has created a fully-fledged Dantean world with its own effective symbology, freed from the Ironic in its various forms: a century-long winter, an invasion, a young boy’s modern prejudices, a contemporary school’s educational system and a quasi-Arabic medievalism. Just as Dante’s world revolved around the Christian God, Lewis's Epic universe is now in orbit around a Godhead in the new symbolic form of a Lion, able to defeat Death itself, intimately involved in events and in the life stories of its characters throughout the chronicled history of Narnia.
What remained was to chronicle its beginning and its end.