Illyrio Mopatis

"What good is war now? We're not ready."

- Illyrio conspiring with Varys

Illyrio Mopatis is a recurring character in the first season. He is played by guest star Roger Allam and debuts in the series premiere. In the unaired pilot episode he was played by Ian McNeice, but due to a scheduling conflict the role was recast when the pilot was re-shot. Illyrio Mopatis is a Magister of Pentos and a supporter of House Targaryen.

Background
Illyrio is a Magister (merchant-lord) of the Free City of Pentos, located across the Narrow Sea to the east of Westeros. Immensely rich and powerful, Illyrio is an ally and benefactor to Viserys and Daenerys Targaryen.

Season 1
Illyrio brokers the deal to "sell" Daenerys in marriage to Khal Drogo of the Dothraki. Drogo desires an exotic wife from far away and Viserys needs a Dothraki army to help retake the Seven Kingdoms, so a bargain is made. Illyrio is present when Daenerys says that she doesn't want to marry him. Viserys says she will: he would let Drogo's men and their all their horses have sex with Dany if it meant that in return he could get an army to retake his throne with. She's lucky she only has to sleep with the Khal. When Drogo comes to approve of Daenyrys, he rides up to the steps, looks her over, and then rides off. Viserys is concerned as Drogo had not said a word nor had he even dismounted. However Illyrio assures him that if Drogo had not approved, he would have made it known.

Illyrio hosts the wedding and gifts Daenerys with three dragon eggs, turned to stone by the passing of ages. He introduces them to Ser Jorah Mormont, a Westorosi lord in exile who then takes service with Viserys. Khal Drogo immediately leaves with his khalasar for Vaes Dothrak, to present Daenerys before the dosh khaleen, and see if the omens are right for war. Ser Jorah tells Viserys that he should stay at Magister Illyrio's estate, as he has been invited to do, until after Khal Drogo returns from the sacred city, but Viserys says he will stay with the khalasar until he gets his army.

Some months later, Illyrio pays a secret visit to King's Landing where he discusses their mutual plans with his ally, Varys, in the secret passages under the Red Keep. Once Khal Drogo's son is born, the Dothraki can move to invade Westeros and Viserys can retake the Iron Throne. However, Westeros must be in chaos and civil war before this happens. When Varys warns that a civil war, launched by a conflict between House Stark and House Lannister, is imminent, Illyrio becomes concerned that things are moving too fast, but Varys suggests motivating the Dothraki to move faster might be a viable strategy. They talk about how new Hand of the King Eddard Stark now has the same genealogy book that his predecessor read, and has met Robert's bastard son Gendry: the same evidence which led Jon Arryn to discover the truth about Queen Cersei's children. They discuss the possibility that the same fate may befall Lord Stark as did his predecessor. Their discussion is overheard by Arya Stark, who is in the tunnels under the Red Keep chasing cats. Arya tries to warn her father about what she heard, but she doesn't know who the speakers were and out of context, all she understood was that it was some plot to trick the Starks and Lannisters into fighting each other.

In the books
In the A Song of Ice and Fire novels, Illyrio is a morbidly obese, middle-aged man who dresses in rich finery. He favors using money and wealth to overcome problems rather than honor and valor. He is politically canny and astute.

According to the TV series official pronunciation guide developed for the cast and crew, "Illyrio" is pronounced "Il-LEAR-ee-oh ", as opposed to "Ill-e-rio", etc.