Janos Slynt

Janos Slynt is a recurring character in Game of Thrones. He is played by guest star Dominic Carter and débuts in the fourth episode of the first season. Janos Slynt is the commander of the City Watch in King's Landing. He was named Lord of Harrenhal for his loyalty to King Joffrey Baratheon. He now heads House Slynt.

Background
Janos Slynt is the commander of the King's Landing City Watch (also called the 'goldcloaks'), with almost two thousand men under his command. He is charged with keeping peace and order in the city and quelling unrest.

Season 1
Janos reports to the small council about the disruptions to the city caused by the tournament to celebrate Lord Eddard Stark's appointment. Lord Renly Baratheon suggests dismissing Janos in favor of someone more competent, but Janos angrily replies he doesn't have enough resources. Eddard offers him twenty of his household guard and commands Littlefinger to find gold to pay for an expansion of the City Watch by another fifty men.

After Eddard resolves to expose Joffrey Baratheon's true birth, he asks for the help of the City Watch. Littlefinger agrees to bribe them into supporting Eddard's plan. Janos tells Eddard that they are with him, but is then seen exchanging looks with Queen Cersei Lannister. During the confrontation the City Watch turns on Eddard and kills his men, allowing him to be taken prisoner. Following Lord Stark's arrest, Janos is created the new Lord of Harrenhal and head of House Slynt by King Joffrey as a reward for his loyalty.

In the books
In the Song of Ice and Fire novels Janos Slynt was a commoner (a butcher's son) who joined the Watch and raised through the ranks to become its commander, as it is one of the few institutions in Westeros to permit promotion of non-nobles from the ranks. He is somewhat humorless man who is arrogant and proud of his achievements.