Aravis Tarkheena is the only daughter of Kidrash Tarkaan, who is said to have descended in a direct line from the god Tash himself. Her mother died (probably when she was 10 or 12) and her father remarried a woman who hated her. Aravis' stepmother arranged for her to be promised in marriage to Ahoshta Tarkaan, but Aravis was opposed to this match and took her mare Hwin and rode out to a quiet spot in a forest, intending to kill herself. But Hwin intervened by speaking to Aravis, who discovered that Hwin was not a dumb horse as she had thought, but was actually a Talking Horse from Narnia who had been captured as a young foal. . Hwin desired to return to Narnia, and Aravis decided to go with her to escape the life that would come to her if she married Ahoshta.
Under the pretense of taking a private pilgrimage to make sacrifices to the Calormen goddess Zardeenah, Aravis and Hwin made their escape. Aravis drugged the maid that was supposed to go with them to prevent her following them, and, disguised as a Calormen soldier, Aravis and Hwin left.
They met up with Shasta and Bree when a lion forced them to join paths, and Bree and Aravis agreed to travel together since there was strength in numbers. Shasta resented Aravis' presence and Aravis paid little attention to him. To her, he was merely a peasant boy who was only traveling with her because Bree insisted on it.
Trouble arrived when the group attempted to pass through the city of Tashbaan. When Shasta is mistaken as an Archenland prince and is taken by a group of Narnian lords, Aravis is thrust in charge and must find a way to get herself and the horses safely out of the city. Lasaraleen, a Calormen noblewoman and friend of Aravis happened to be passing by on her litter, and Aravis seized the opportunity and found a means for getting out of Tashbaan. She had Lasaraleen treat her as a servant girl and Bree and Hwin as ordinary horses, and asked Lasaraleen to show her a way out of the palace. On their way out they inadvertently eavesdrop on a top secret meeting between the Tisroc, his son Rabadash, and Ahoshta Tarkaan, in which they hear that Rabadash plans to invade the country of Archenland lay siege to the castle of Anvard.
The girls manage to escape without being seen, and Aravis takes Hwin and Bree to the Tombs, where they meet up with Shasta. The two combine the knowledge that they have gained during their separating, and they decide to cross the desert and try and warn King Lune of Archenland before Rabadash arrives.
The journey across the desert was treacherous and difficult, and Aravis is wounded when a lion attacks the group and claws her shoulder. They find refuge in the dwelling of the Hermit, and Aravis and the horses remain there when Shasta is sent off on foot to warn Anvard of the invasion.
Aravis meets Aslan during her stay with the Hermit, and he tells her he was the Lion that forced her to join up with Shasta and that clawed her back as a punishment for her indifference to her maid's plight when she drugged her and left her to be beaten.
After the Siege of Anvard, Aravis went to live in the castle with King Lune and his two sons, Cor (formerly Shasta) and Corin. She and Cor still had quarrels, but as they grew older they were so used to quarreling and making up that they decided to get married, so as to do it more conveniently. They had a son, Ram the Great, who was said to be the greatest Archenland king of all times, and Aravis is counted among the faithful at the Great Reunion in Aslan's Country.