Petyr Baelish

Petyr Baelish, popularly called Littlefinger, is a major character in the first, second, third, fourth and fifth seasons. He is played by starring cast member Aidan Gillen and debuts in "Lord Snow." Petyr Baelish was 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. Baelish's spy network is eclipsed only by that of Varys. He betrayed Eddard Stark to side with House Lannister and King Joffrey Baratheon following the death of King Robert Baratheon, becoming one of the instigators of the War of the Five Kings. Following the events of the Battle of Blackwater, King Joffrey named Littlefinger the Lord of Harrenhal. He eventually marries Lysa Arryn and proceeds to murder her shortly afterwards, becoming Lord Protector of the Vale until Lord Robin Arryn comes of age and one of the most powerful men in all of Westeros.