Xaro is a powerful merchant established in the great city-state of Qarth.
Xaro Xhoan Daxos is a powerful merchant prince of the great city of Qarth born on the Summer Islands, located far to the south of the Dothraki sea, beyond the Red Waste. He is a member of the Thirteen, an organization that rules over Qarth.
He boasts of being the wealthiest man in Qarth. In Qarth, a merchant invited into the Thirteen remains in his seat for as long as he is feared or respected enough not to be denied membership by his other twelve peers.
Xaro Xhoan Daxos has heard rumors concerning the return of magic into the world. Among them are glass candles burning, ghost grass growing far away from the Shadow Lands and a Dothraki khalasar led by a woman with three heads, persumably Daenerys Targaryen and her dragons.
Xaro and the Thirteen meet Khaleesi Daenerys Targaryen at the gates of Qarth, weeks after the Thirteen met with Daenerys' bloodrider Kovarro. They demand to see her dragons and when she refuses they deny her admission to the city. Xaro invokes the ancient custom of Sumai to allow her and her people to be admitted under his protection. Xaro welcomes Daenerys to the city and makes her a guest in his expansive mansion. He makes repeated references to the fact that he came to Qarth with nothing, but by skill and determination has made himself the richest man in the city.
Xaro hosts a lavish reception for Daenerys in his gardens to introduce her around to Qarth's social elites, and showers her with gifts. Later that night, he shows her his massive treasure vault which is impossible to open without the key he always wears around his neck. Inside is his enormous fortune which he promises to divide with her if she will marry him. Xaro informs Daenerys that news has reached Qarth that King Robert Baratheon is dead, and the subsequent outbreak of the War of the Five Kings which is tearing Westeros apart. Daenerys learns that the major noble Houses which played an active role in deposing House Targaryen are now fighting each other: Robb Stark is fighting the Lannisters, and the Baratheons have been split between Robert's two younger brothers, Stannis and Renly
Daenerys is at first excited by this news, as she has lived in fear of Robert Baratheon her entire life. More importantly, the outbreak of the War of the Five Kings means that House Targaryen's enemies are now divided. She seriously considers Xaro's offer of a marriage-alliance, as he can provide her with enough money to raise an army to invade Westeros with. Her advisor Ser Jorah Mormont is more hesitant, however, stressing that men like Xaro only want something in return. Daenerys acknowledges that Xaro has openly admitted that he hopes to become even wealthier if Daenerys reconquers Westeros as his wife, but Jorah points out that this won't simply be rewarding Xaro: the lords of the Seven Kingdoms will say that it was Xaro's conquest, achieved with resources he provided, and Daenerys will become little more than a figurehead
Initially eager to take the quickest path back to Westeros, Daenerys eventually relents to Jorah's advice and decides to decline Xaro's offer for the moment. Instead she tries to secure support for her return to Westeros from his colleagues in the Thirteen, but without success. While they are meeting with the Spice King her dragons are stolen from Xaro's home. One of Daenerys' maids Irri is dead while the other, Doreah, is missing and presumed dead. Xaro uses the theft as a premise to hold a council of the Thirteen in his home. He then stages a coup with the assistance of the warlock Pyat Pree and declares himself King of Qarth. The warlock uses his magic to kill the rest of the Thirteen. They reveal that they stole the dragons and have taken them to the House of the Undying. Daenerys flees in terror.
Daenerys later escapes from the House of the Undying after retrieving her dragons and with her men invades Xaro's house where she finds Xaro in bed with Doreah, revealing that she had in fact betrayed Daenerys and her dragons to Xaro and Pyat Pree. Xaro and Doreah plead for their lives, with Xaro promising to get her ships to invade Westeros. Using the circular key pendant, the treasure vault is opened and found to be empty, his enormous wealth a lie to cling on to his power. Xaro and Doreah are locked inside the merchant prince's vault to die, and Daenerys and her people ransack Xaro's house of all its gold and precious items, which Ser Jorah says will be enough to buy a ship.
A wealthy spice merchant from Qarth, Xaro Xhoan Daxos was the member of the Thirteen who spoke up for Daenerys Targgryen when she arrived in Qarth. He conspired with Pyat Pree to take the city and Dany's dragons, and was locked in his empty vault when Daenerys discovered his treachery.