Medieval war imagery
Firearms and gunpowder are unknown in Narnia, Archenland, and Calormen at this point, so war is carried out in a medieval fashion. Armored fighters, typically of the wealthier noble class, travel about on horseback and fight from horseback. They are armored chiefly in mail, they carry shields, and they fight with swords or lances. The Calormene style of armor and weaponry is reminiscent of 12th and 13th century Turkish and Persian technology, whereas Narnian and Archenlander arms and armament resemble medieval European technology.
Slavery imagery
At the beginning of the novel, Shasta is to be sold as a slave and Aravis is living in oppressive conditions so repugnant to her that she persuades her father to offer her in an arranged marriage simply so that she can escape with Hwin, her talking horse. Bree, another talking horse who is escaping from his Calormene owner, is the one who persuades Shasta to flee.
The fact that slavery is common in Calormen but not in Narnia or Archenland is one of the things that sets the Calormene noblemen up as antagonists.
Equine imagery
Two of the most significant characters in the novel are talking horses, and Shasta and Aravis spend a great deal of time in the saddle, so it is natural to expect that horses, saddles, bridles (which are worn by the talking horses sometimes for appearance), and other horse related imagery appears throughout the book.
Following his defeat, the aggressive prince Rabadash is transformed by Aslan into a donkey, which suggests stubbornness and foolishness. The transformation will be reversed if he goes to his own temple in Tashbaan and shows appropriate submission, but if he strays more than ten miles from the temple the transformation will return permanently. This keeps Rabadash from trying to invade Archenland and Narnia again during his lifetime.
Twin imagery
Shasta, unbeknownst to anyone, is the twin brother of Corin, the Crown Prince of Archenland. In fact, he is the elder of the two and is therefore the rightful heir to the throne. But twins and pairs appear throughout the book.
Shasta and Aravis, the two young escapees from Calormen, are a pair. They develop a strong loyalty to one another despite an initial mutual dislike and eventually marry. Bree and Hwin, the two talking horses, make up another pair. The younger two rulers of Narnia, Edmund and Lucy, are siblings and also appear as a pair.
Several different kinds of pairs are represented: same-gender and different-gender siblings, mixed-gender platonic friends such as Bree and Hwin, and even a brief appearance of Aravis's best friend Lasaraleen, who helps Aravis to escape the capital city.
