Shireen is the daughter and only child of Stannis and Selyse Baratheon.
Shireen is the daughter of Stannis and Selyse Baratheon. Her father is the head of House Baratheon of Dragonstone and has declared himself King on the Iron Throne. Shireen is Stannis's only living child and therefore his heir presumptive. She is the same age as Arya Stark. She had three older brothers, who were stillborn.
The left side of her face is scarred by Greyscale.
Shireen was not born a princess, but was born into a powerful noble family. She only recently became a princess, after her father declared himself king upon her uncle King Robert's death.
Though Selyse resents Shireen, dismissing her as cursed, stubborn and sinful, Shireen shares a strong relationship with Stannis, who loves her dearly.
Having ignored Selyse and Shireen for several months, Stannis pays them a visit sometime after Melisandre's departure from Dragonstone to gather power on the mainland. Selyse tries to dissuade Stannis from seeing Shireen, but he angrily insists upon seeing his daughter. While telling her of the disaster at Blackwater Bay, Shireen asks for Davos Seaworth, calling him by his traditional soubriquet, "The Onion Knight". Stannis gently explains that he is a traitor and is in the dungeon, a notion which distresses the young princess. Advising her to forget her friend, Stannis departs. Later that night, Shireen sneaks out of her tower and into the dungeon to see Davos. She demonstrates knowledge of the guards and their habits, making sure to visit when the gaoler, a known drunk, is on duty. Shireen brings Davos a book about Aegon the Conqueror to pass the time, but the Onion Knight admits he cannot read. Shireen takes this in stride and begins to teach him through the bars of his cell.
Following Ser Davos's release, he spends time with Shireen. She implores him to read more of Aegon's exploits rather than sort through Stannis's correspondence, which consists mostly of invitations to attend social events thrown by his few remaining bannermen, including the nameday celebration of one of Shireen's Florent cousins. When a confused Davos asks why there is a "G" in the word "night", Shireen shrugs off the unusual spelling.
Selyse fears for Shireen's soul, saying that she is stubborn, sinful and sullen. She expresses a desire to strike her with a rod, which Stannis forbids. Selyse suggests that Melisandre speak to Shireen. Melisandre goes to visit her and Shireen makes clear her disapproval of Melisandre burning people, including her uncle Ser Axell Florent. Melisandre tells her that the tales told in the Seven-Pointed Star are lies and fables and that the only true gods are R'hllor and the Great Other, with the only hell being the one they live in now.
Reacting to the news of Joffrey's death at his own wedding, Stannis is still discouraged because he does not have sufficient remaining soldiers to seize on this opportunity. Davos suggests that they could attempt to hire mercenary companies from the Free Cities, but Stannis scoffs that they don't have any gold left either.
Later, Shireen continues her reading lessons with Ser Davos in her chambers. She scolds him for being late, and insists that he won't make a very good Hand of the King if he sees the word "knight" and says "ka-nigit". He says that she certainly is her father's daughter, as they are both relentless. She gives him a new book which she says is more complex, The Life and Adventures of Elyo Grivas, First Sword of Braavos. She chides him for moving his lips when he reads because that's how children do it, then claps her hands in congratulations when he reads the title correctly. Shireen says she enjoys this book because it is filled with pirates and swordfights.
Davos explains that he has been to Braavos, during his smuggling days, but he nearly lost his life when he ran afoul of the First Sword who was protecting the ships of the Iron Bank of Braavos. Davos says that's to be expected, though, given that the ships of the Iron Bank transport a nation's worth of gold - at which point realization suddenly dawns on him. Davos kisses Shireen on the forehead for having helped him figure it out and asks her to write a letter to the Iron Bank. She protests that he really should because it is good practice, but says that it is very important, so he must make sure that it is written properly by someone smart. He proceeds to dictate a letter requesting for an audience with the Iron Bank, to ask them to switch their support from the Lannisters to her father. He has her address the letter as if she was actually her father, and she asks if they should do that: Davos says it is fine (given that he is Stannis's Hand) and that addressing the letter as "from King Stannis" is just to get the Bank's attention.
Shireen accompanies Stannis to the North in his defense of the Night's Watch against the wildlings. She and her mother are present in Castle Black at the Watch's subsequent funeral for their fallen brothers.
Shireen, alongside her mother, are present when Mance Rayder is executed by Stannis Baratheon for refusing to bend the knee. While her mother looks pleased, Shireen is horrified and closes her eyes when Mance starts to burn.
Since Gilly is illiterate, Shireen begins to teach her letters with Samwell Tarly watching the two. Shireen also tells the two of them how she contracted Greyscale when she was little and survived. Gilly and Sam leave when Shireen's mother enters and begins to scold her about fraternizing with a wildling girl. Shireen tries to defend Gilly, but Selyse criticizes her for being naive despite all the knowledge she has gained from her books.
Shireen watches Jon Snow spar with new recruits in the courtyard of Castle Black. Later, she visits her father in his chambers. Stannis asks his daughter if she is lonely, but Shireen is simply bored. He knows that Castle Black is not a place for a child, but Shireen is glad to be there since she believed that she would be left behind at Dragonstone. Finally, Shireen asks her father if he is ashamed of her. The question surprises Stannis, but he responds by telling Shireen the story of how she contracted greyscale from a doll he bought from a Dornish merchant. Although he was counseled to send her to the ruins of Valyria to live out he short life with the Stone Men, Stannis did the exact opposite and called every maester, apothecary, and healer he could find to save his daughter's life. Overjoyed, Shireen embraces her father and he returns the embrace.
When Stannis and his army leave Castle Black for Winterfell, he takes Shireen and Selyse with him, not wanting them in the company of the Night's Watch, due to many of them being criminals and rapists. As they depart, Shireen tells Davos that she wants to see the crypt of Winterfell where all the old Kings in the North are buried, to which Davos replies that they must first take the castle from the Boltons. Shireen asks him if there is going to be a battle, and he affirms that she won't be anywhere near it. Selyse approaches them and commands Davos to stop speaking of battles and scaring the child. Shireen claims that she is unafraid, and promises to protect him. Shireen rides from Castle Black along with the Baratheon army.
However, during the march the weather turns for the worse and a snow storm delays Stannis' army. Melisandre reminds Stannis that they may need to sacrifice more King's blood in order to better their chances of winning the upcoming battle in the snow which they both saw in the flames, citing the deaths of Robb Stark and Joffrey as examples. When Stannis says that they have no chance of locating Gendry, Melisandre suggests that they sacrifice Shireen. Stannis is visibly shocked and disgusted by the suggestion, asking her if she has lost her mind. She tries to convince him but he rebuffs her and orders her to leave his presence.
Things get worse for Stannis and his army when Ramsay, along with twenty other Bolton soldiers, sneak in and destroy the food tents and kill some of the horses. The desperate nature of Stannis' position suddenly becomes clear. Before Davos is sent away to the wall to retrieve more supplies and men, the onion knight visits Shireen in her tent and presents her with a beautifully carved stag. Grateful of his gift, Shireen thanks Davos and sends him off with a heartfelt goodbye. Stannis later visits Shireen and the two discuss the events that unfolded between Rhaenyra Targaryen and her brother Aegon during the Dance of the Dragons. Stannis tells her if a man knows what he is and remains true to his self that he must fulfill his destiny no matter how much he hates it. Shireen, being the loving daughter she is, expresses to him that she wants to help and will do whatever she can to help her father without knowing his true intentions. As Shireen embraces her father, Stannis asks for her forgiveness.
Later on Shireen is escorted and tied to a pyre where she is sacrificed to the Lord of Light by Melisandre. As she burns she pleads for her mother and father to help her. Selyse runs to her daughter's aid, but is held back by Baratheon soldiers, and crumples to the ground as she watches her daughter die by the flames and Stannis looking away with tears in his eyes.
Shireen's sacrifice allows her father's army to press forwards as the blood magic appears to have been successful in melting the the snows. However, the horror of a little girl's sacrifice has made hundreds of Baratheon troops and all his sellswords (about half his army) desert, while Selyse hangs herself. Stannis nevertheless presses forward to Winterfell but his army is defeated by the Boltons. Stannis is later killed by a vengeful Brienne of Tarth, his spirit broken by defeat and the sacrifice that was far too dear.
Stannis and Selyse's only child, Shireen suffered from disfiguring greyscale at an early age. She was close with her father's Hand, Davos Seaworth, who always had her best interests at heart. Stannis sacrificed Shireen to the Lord of Light at Melisandre's urging.