Cersei Lannister -
Meanwhile, as Stannis Baratheon, (who as Robert Baratheon’s eldest brother, has proclaimed himself King of the Seven Kingdoms, etc., etc.) sails from Storm’s End to Blackwater Bay to claim the Iron Throne, she huddles with the noble women of King’s Landing in the Maegor’s Holdfast. They are joined by Ilyn Payne whose duty, as she explains it to Sansa, is not to protect them, but to execute all within should the city fall. As Stannis’ troops land, Cersei takes her son, Tommen, to the Iron Throne and, believing all is lost, prepares to poison Tommen and herself. As she raises the poison vessel to Tommen’s lips, the doors of the throne room are thrown open and Tywin, who has torn himself away from the war with Robb, strides in proclaiming that the battle is won and Stannis’ army is routed.
Cersei is delighted when Tywin assumes the role of Hand of the King and Tyrion is stripped of his power. However, she is quickly put in her place when Tywin announces that she will marry Loras Tyrell (the gay brother of Margeary.) Not only has her father usurped her power, but now is to be bartered her off like a prize cow.
When Jaime finally returns, accompanied by Brienne of Tarth, Cersei is shocked to find him missing his sword hand. (It was cut off by one of Roose Bolton’s men who recaptured him after he had escaped from Robb’s capture.)
At the wedding feast for Joffrey and Margaery, Cersei smiles as Joffrey makes a fool of Tyrion by demanding that he be his wine bearer. When Joffrey dies from poisoned wine served by Tyrion, she finally sees her chance to do away with hated brother by declaring him Joffrey’s murderer.. When it appears that Tyrions seconds are numbered, he is saved from execution by Jaime (who loves his brother dearly). As he makes his escaped, Tyrion comes across his father, Tywin, sitting on the royal throne (that would be the crapper). After a short “conversation” in whick Tywin takes his usual demeaning manor, Tyrion puts two crossbow bolt through Tywin, thus ending his tyrannical ways and cutting short the royal dump. Though Cersei morns her father’s death for several seconds, she is now not only freed from marriage with Loras, but, with the crowning of Tommen as King, also regains her power over the Throne.
Just when things are looking up, she receives a box from Dorne that contains a stuffed red viper with Myrcella’s necklace in its jaws. She agrees that Jaime will go to Dorne to bring her back.
When Tommen marries Margeary (this would be her third marriage to a king), Cersei sees her powers again begin to slip away. In a move to weaken the Tyrells and, hopefully, their influence over Tommen through Margeary, she calls the High Sparrow to her and names him the new High Septon. She then suggests that he reinstate the Faith Militant, the military order of the Faith of the Seven, to enforce their laws which results in the arrest of Loras Tyrell. However, Cersei’s plans backfire when she is taken by the High Sparrow for sins with her cousin Lancel. (Lancel was Cersei’s lover during Jaimie’s absence and later became a henchmen of the Faith Militant.) After spending time in a dungeon cell, harassed by Septon Unella, Cersei accepts a “walk of atonement” for her relaese. She is stripped naked, her hair is shorn and she walks the distance from Baelor’s Sept to the Red Keep. Along the way she is spat upon, mooned and battered with rotten stuff and even human feces.
On her shameful return, she is covered by a blanket and carried by “MountainStein”, the rebuilt Mountain (Ser Gregor Clegane) that was nearly killed (or was he killed?) by Oberyn Martell.
Later she is alerted to Jaime’s return from Dorne and rushes to the port to meet him and her daughter Myrcella. Here she sees Myrcella’s corps covered in a golden robe and learns she was poisoned by Ellaria Sand (Oberyn Martell’s paramour). She realizes that the witch’s prophecy was, in fact, true.
When Cersei hears that the Faith Militant has entered the Keep, she confronts them, accompanied by MountainStein. Lancel, who is leading the FM, tells Cersei to order the MountainStein aside or there will be violence, Cersei replies (and one of may favorite quotes of the series) “I choose violence!” One of the FM then attacks the MountainStein and he retaliates by literally ripping his head off and tossing it aside. Lancel and his men back down. (Duh!)
Later, Tommen declares that the Crown and the Faith are the two pillars of the kingdom. He then announces Cersei’s trial and that, henceforth, trial by combat is forbidden. With this, she truly knows that Tommen is in the clutches of the High Septon. When she learns of the existence of wildfire beneath the Sept of Baelor, she plots her revenge. On the day of her trial, she ignites the wildfire beneath the Sept killing all within, including the High Septon, all of the FM, Margaery, Loras and Mace Tyrell and her uncle Kevan who had taken Tywin’s place as head of the family, thus sweeping her enemies from the playing table.
Tommen, who has been detained by the MountainStein from attending the trial, views the destruction of the Sept including his wife Magaery, from his window in the Red Keep. In his despair, he steps to the window sill and falls forward to his death. Thus are three of the witch’s prophesies fulfilled.
As season six ends, Jaime is returning from his defeat of the Tullys. He sees the smoke and ruins of Baelor’s Sept from afar. (Here we should remember that Jaime murdered the Mad Targaryen king for threatening to explode the wildfire stored beneath King’s Landing and “kill them all!”) In their final scene he walks into the Throne Room just as Cersei is crowned Queen of the Seven Kingdoms, etc., etc. As she first sits the Throne, their eyes meet and only Season 7 will reveal its meaning.