The truth of Game Of Thrones inciting incident has been revealed [Recap: season 4, episode5]

AND SO, TIME marches on. Joffrey Baratheon is no more, and Tommen, First Of His Name, owner of the cuddly Ser Pounce, rises to take his place on the throne. But hes just a boy, able to be pushed around by the blustering of his advisors and those who seek to gain power in Kings Landing. Tywin has Tommens earespecially after that birds and bees talkand Margaery has her secret visits, but according to Olenna Tyrell, shell have to out-maneuver Cersei to finally secure her place beside the Iron Throne as Queen.