Background. This Baratheon was Cersei Lannister's firstborn child, and the only one of her children to actually be fathered by her lawful husband, King Robert Baratheon, making him the only trueborn child of both parents.
Who's the father of Cersei's child? The father, based on the all the evidence and context, is again Jaime Lannister, Cersei's brother. The first time we heard about the pregnancy was back in season 7, when Jaime was still knocking around King's Landing.
Cersei has been involved in an incestuous affair with her twin brother, Jaime, since childhood. All three of Cersei's children are Jaime's, which is unbeknownst to Robert. The rumored illegitimacy of her children causes a power struggle in the wake of the king's death, known as the War of Five Kings.
She got pregnant by Robert once but Jamie found a woman to "cleanse" Cersei - I.e., abort the pregnancy. In the show, she and Robert had one child together but the baby, a black-haired boy, "died of a fever" soon after he was born. Cersei and Robert even talk about it later on in the season.
Technically, she's had four, but in Season 1, she told Catelyn Stark how her first, a “black-haired beauty” she had with Robert, died of fever shortly after his birth. If Maggy's prophecy is correct, we can expect tragedy in Cersei's fifth pregnancy as well.
But in the process of trying to reason with his sister, Tyrion may have unintentionally turned the tide in Daenerys' favor. Earlier in the episode we saw Cersei tell Euron that she was pregnant and that he, not Jaime, was the father.
Throughout Season Eight, which in all likelihood took place over a minimum of a few weeks, Cersei never appeared to be pregnant, even though she also told Euron that she was carrying his child. Again, this could have been a tactic to keep his loyalty, as he wanted to father a king.
Following the war, Robert married Cersei Lannister to ensure political stability. With her, Robert has three children: Joffrey, Myrcella, and Tommen. In the television adaptation Game of Thrones, Robert is portrayed by Mark Addy.
Books. Queen Cersei Lannister is a member of House Lannister and the eldest child of Lord Tywin Lannister. She is the Queen of King Robert Baratheon, and has three children, Joffrey, Myrcella and Tommen Baratheon.
Princess Myrcella Baratheon is known to the Seven Kingdoms as the middle child of King Robert Baratheon and Queen Cersei Lannister. A member of House Baratheon of King's Landing, her siblings are Princes Joffrey and Tommen.
While Cersei was promised to Prince Rhaegar Targaryen as a young girl, he ended up marrying Elia Martell before being killed by King Robert Baratheon — Cersei's eventual husband.
After Robert's Rebellion, Cersei married King Robert I Baratheon and became Queen of the Seven Kingdoms. She is the mother of Prince Joffrey, Princess Myrcella, and Prince Tommen of House Baratheon of King's Landing.
[3] When Cersei was a girl, her father promised her that she would marry Prince Rhaegar and would one day become queen. She was delighted by this news and became infatuated with Rhaegar upon their first meeting. However, King Aerys rebuffed Tywin's offer, later marrying Rhaegar to Elia Martell.
When Cersei has an affair with Lancel Lannister, their cousin. Cersei sleeps with their cousin Lancel throughout seasons one and two. Lancel does everything she asks him to, including causing the death of King Robert. In season five, Lancel confesses the affair and the death of Robert to the High Sparrow.
But Headey found an understanding in the scene by keeping the perspective that Cersei was sleeping with Euron as a way of preserving her power and alliance. "Cersei is such the ultimate survivor in all of this," Headey told EW. "She refuses to fall to her knees. She goes to the place where she doesn't want to go."
When the series first began, Cersei had three children, ostensibly with her husband, King Robert Baratheon, but actually fathered by her twin brother and secret lover, Jaime Lannister. As Game of Thrones enters its final season, all three of those children are long dead.
2. When she mourned Joffrey's death. Obviously, it was a treat for viewers to see young Joffrey get his just desserts, but the way Cersei was absolutely wrecked by his death kind of dampened the mood. For whatever reason, Joffrey was her favorite, her baby boy, and he burst like a rotten blister.
Cersei almost uses the poison on Tommen, to prevent him from being captured when the battle seems lost.
Both Jaime and Cersei Lannister are 35/36 as the Game of Thrones kicks off, reaching 43 by the final season and presumably enjoying extravagant 40th birthday parties in between incestuous romps and repelling angry Northerners.
Gendry Baratheon is the true heir of Robert, as Ned wrote when Robert was on his death bed.
There is no hint in the books that Robert suspected the children were not his, however he did know the nature of Joffery but chose to ignore it. He admits to Ned that he knows what his son his, so that means he didn't suspect they weren't his children.
They made Tommen a bit older on the series, but actor Dean-Charles Chapman was still 16 years old when he filmed the scene... while his scene partner Natalie Dormer was 33.
In Season 1, Daenerys married Khal Drogo and became pregnant with their son, Rhaego. The child was stillborn, presumably due to Mirri Maz Duur's blood magic. The witch ultimately used Rhaego's life to help restore Drogo, who remained in a vegetative state and never recovered.
But as it turns out, Cersei really was pregnant. And as Lena Headey recently explained, one very important scene for the character ended up being cut—one that would have cast her in a very different light in the final season.