The massacre in the Red Keep was the result of Lord Eddard Stark's failed attempt to place King Joffrey Baratheon and his family under arrest to ensure the coronation of Robert Baratheon's true heir, his brother Stannis. Alongside the attacks against the smallfolk of the Riverlands carried out by House Lannister, this was one of the key events in the detonation of the War of the Five Kings.