Petyr Baelish

Petyr Baelish, popularly called Littlefinger, is a major character in Game of Thrones. He is played by starring cast member Aidan Gillen and debuted in the third episode of the first season. Petyr Baelish is the Master of Coin on the small council. He is a skilled manipulator and uses his ownership of brothels in King's Landing to accrue intelligence on political rivals. He betrayed Eddard Stark to side with House Lannister and King Joffrey Baratheon following the death of King Robert Baratheon.

Background
Petyr Baelish is Lord of the Fingers, an extremely minor lordship, ruling over just a small area of the shores of the Vale of Arryn (known as The Fingers) as the head of the tiny House Baelish. Despite this, his extreme financial acumen has seen him rise to the small council and the rank of Master of Coin, the treasurer of the Seven Kingdoms, under King Robert Baratheon. He is a friend of Lady Catelyn Stark, one of the few contacts she has at court. He was fostered with her family at Riverrun in his youth and developed unrequited feelings for her. He challenged her betrothed Brandon Stark to a duel and was severely injured. Brandon was later killed by King Aerys II Targaryen but Catelyn married his younger brother Eddard Stark in his place. He owns a number of brothels in King's Landing. Though the symbol of his family is the head of the Titan of Braavos, Petyr prefers to use a personal sigil, that of an unthreatening mockingbird.

Season 1
Littlefinger greets Eddard upon his arrival in King's Landing and reports that the realm is six million gold dragons in debt, half of it owed to House Lannister. Catelyn Stark and Ser Rodrik Cassel attempt to sneak into the city, but are spotted by one of Littlefinger's men. They are taken to meet Littlefinger at one of his brothels. Catelyn is angered by their treatment, but asks Littlefinger for aid. She is trying to identify the people who tried to have her son Bran Stark killed. Littlefinger is able to answer this quickly: the elaborate dagger wielded by the assassin used to be his, but he lost it in a gamble with Tyrion Lannister.

Littlefinger fetches Eddard to meet his wife, but when Eddard realizes he was being brought to a brothel, he thinks Littlefinger is insulting him by saying his wife is a whore. Eddard throws Littlefinger up against a wall before Catelyn appears and Eddard becomes pacified. After hearing her news, he vows to find the truth and expose the Lannisters to Robert and Littlefinger agrees to be his ally in this, for the affection he once bore Catelyn as a youngster. Eddard believes that Littlefinger is still in love with his wife.

Littlefinger attaches himself more firmly to Eddard's cause, giving him information that leads Eddard to Tobho Mott's smithy. He also points out some of the agents belonging to the Queen and to Varys. He later tells Sansa Stark about how Sandor Clegane has his face burned by his brother when he was young for stealing a toy. He advises her not to mention the matter to Sandor.

Littlefinger loses a bet to Renly Baratheon over the joust between Ser Loras Tyrell and Ser Gregor Clegane. He makes it clear that he knows about Renly's sexual relationship with Loras, to Renly's discomfort. Littlefinger and Varys verbally spar, Littlefinger threatening to reveal to the King that Varys has been meeting with Illyrio Mopatis in secret whilst Varys threatens to reveal to the Lannisters that it was Littlefinger who implicated Tyrion in the attempted murder of Bran Stark. However, they then both support the motion to have Daenerys Targaryen assassinated before the Dothraki can invade Westeros.

Littlefinger later introduces Eddard to Mhaegen, a prostitute and mother of yet another of King Robert's bastard children. Outside the brothel Eddard gets into a fight with Ser Jaime Lannister. Littlefinger flees, promising to return with the City Watch.

Littlefinger is stunned when Eddard orders that Gregor Clegane be arrested and executed for his raids on the Riverlands and when he also orders Tywin Lannister to present himself at court to answer for his bannerman's crimes. Littlefinger reminds Eddard that Tywin is the richest man in Westeros and that it is gold that wins wars, not armies. Eddard disagrees, asking why then Tywin is not the king.

Littlefinger tutors a new recruit to his brothels, Ros, and discusses his ambitions with her. Later, Eddard tells him the truth of Joffrey's parentage and his plan to install Stannis on the throne when Robert dies.

Littlefinger suggests instead that they let Joffrey rule but act as the powers behind the throne. If he does not mature into the king they want, they can expose his dirty secret and install Lord Renly instead. Eddard rejects the plan as treason and instead asks Littlefinger to win over the City Watch to their cause. Littlefinger agrees, but later the City Watch turns on Eddard's men and kills them, whilst Littlefinger holds a dagger to Eddard's throat, pointing out, "I did warn you not to trust me."

Lord Baelish asks the Queen to allow Sansa Stark to prove her loyalty as he attends the girl’s audience with the Queen and the council. He stands with the st of the council as the details of Joffrey’s reign are read out and Barristan Selmy’s position is ordered to be taken up by Jamie Lannister. He glances suspiciously at Varys as Sansa seeks pardon for her father’s actions.

Baelish watches on as Eddard Stark confesses at his trial and is executed.

Littlefinger discusses kingship with Varys, and they engage in banter revolving around the Master of Whispers’ lack of genitalia.They eventually acknowledge their mutual admiration and respect of one another before being interrupted by Joffrey and his entourage.

In the books
In the Song of Ice and Fire novels, Petyr Baelish's father made the acquaintence of Lord Hoster Tully during the War of the Ninepenny Kings, where they fought together. On the basis of this acquaintence, Petyr was sent to foster at Riverrun, where he met Hoster's own daughters, Catelyn and Lysa. Lysa developed a crush on Petyr, but Petyr preferred the older, more unobtainable Catelyn. When Catelyn was betrothed to Brandon Stark of Winterfell Petyr challenged Brandon to a duel of honor for Catelyn's hand, but was roundly defeated. Petyr returned home. He was later appointed as a customs official in Gulltown, the main city of the Vale, and his extreme success in raising funds led Lord Jon Arryn, the Hand of the King, to appoint him to the small council as Master of Coin, a task at which Petyr has excelled.

'Littlefinger' is a nickname given to Petyr by Edmure Tully during their time at Riverrun together. It is a reference to the fact that Petyr Baelish's holdings are on the smallest of the Fingers, the numerous headlands and peninsulas protruding into the Narrow Sea on the Vale's east coast.