How Much Time Has Passed on Game of Thrones? A Reasonable Timeline, Explained

The Maesters declare Summer is over, and Autumn officially begins. In episode five, "The Ghost of Harrenhal," Renly's death is said to take place 18 years after Robert's Rebellion, which confirms a year or more has passed since the first season. The rest of the season doesn't offer up much in terms of firm dates, but by the time the Battle of Blackwater happens in episode nine, it's been close to two years since Arya and Sansa left Winterfell for King's Landing with their father in the series premiere.