For the past ten years, ever since overthrowing the Targaryens, Robert Baratheon had ruled in King's Landing. After a devastating war, Westeros was at peace. The realm was in the middle of one of the longest summers in history, and all the way from the Wall to the Reach, the land was prospering. Lords feasted all across the realm, and the closest thing to a war was the melee in one of the many tournaments Robert threw. If you asked anyone, from a common peasant to the most noble knight to the richest lord, they would tell you that it felt like the summer was never going to end.
Even the longest summers come to an end, however. Although the majority of the realm was happy with Robert sitting on the Iron Throne, there were still those lords who were not. Two lords, in particular, wanted nothing more than for Robert's rule to come to an end. They plotted behind Robert's back, and slowly, mustered forces to rebel against Robert. However, these Usurpers made sure that no one was unable to uncover their identities.
One day, Varys came to Robert's chambers in secret. "My lord....I fear I have a predicament." He told Robert that he had heard whispers from the corners of the realm that a plot to overthrow Robert had been undertaken. "Unfortunately, my lord, I do not know the identity of these villains." He then suggested that Robert called a council of the greatest lords in Westeros. It would allow the Loyalists to prove themselves, and allow us to keep our enemies closer..."
Ravens went out all over Westeros. From Dorne in the South, to the Iron Islands, to Winterfell in the north, the greatest lords in Westeros came to King's Landing. They gathered in the council room behind the throne room. There, with Robert at his side, Varys stood to address the lords:
"My lords, thank you for coming. I'm sure you have all heard by now of the rebellion raging across our lands. It is of utmost importance that we find the leaders of the rebellion, and end them immediately. For there is nothing more important than peace.
We have reason to believe that the leaders of the rebellion sit among us today. If you are truly loyal to Robert, you will take it upon yourself to identify the usurpers, and deliver their heads to Robert!
When you play the game of thrones, you win or you die. And we have no intention of allowing these usurpers to win. My lords, you have been given your task -- may the gods be with you!"