Cersei and Jaime Lannister are twins…and lovers. Yeah. They are Tywin Lannister's children and Tyrion's older siblings. Cersei is unhappily married to King Robert Baratheon, which makes her queen. (She's not unhappy about that part.) Jaime is one of the knights of the Kingsguard, but since he killed the last king he was sworn to protect, people don't really trust him. Cersei and Jaime have three kids together (Joffrey, Myrcella, Tommen), though it's a secret that those kids aren't actually King Robert's offspring. Cersei conspires against Eddard Stark; and Jaime takes part in the war against the Starks and Tullys, but he is captured by Robb Stark's ambush.
Like all great twin characters in literature, Cersei and Jaime Lannister are incredibly devoted to each other. Unlike the other greats, they also have a lot of sex – with each other. Yikes. There's not much weirder than twincest, especially once you add in the fact that they have kids.
We would love to add a reality check to this (like we've done with most of the Starks) and tell you how old Cersei and Jaime are, but we don't get that information in this book. We also don't get information about their favorite colors or what songs they like to sing. There's actually a lot of information that we don't get about Cersei and Jaime Lannister, because this book isn't really about them. So if you remember the whole incestuous twins thing – and something tells us you will –, you're all set.
The Lannister twins are pretty villainous. So it makes sense that Martin doesn't let us get too far inside their heads yet – that might just make us sympathize with them. In this book, they're supposed to be monsters.
And boy do they rock at being monsters. When Jaime Lannister catches Bran spying on them, he throws Bran off of the tower; he even has a nickname that memorializes what a terrible person he is: "Kingslayer." See, he was one of the Kingsguard, sworn to protect Mad King Aerys, but instead, Jaime killed the guy. Cersei's no better. When she demands that the direwolves be killed after one of them hurts Joffrey, can't you just feel your blood boil?
Basically, Cersei and Jaime never met an opportunity to be villains that they didn't like. Grr. We get mad just thinking about them.
They Can't Be All Bad. Can They?
Now, Cersei and Jaime do have some positive qualities, like their beauty and perseverance. Cersei even comments on how much she loves her children (46 Eddard 12.58), and motherly love is generally a good thing – even if those kids are also her brother's kids, we guess. Ugh.
See that? Almost every time we get a positive for the Lannister twins, we get some reminder of how terrible they are. "Oh, she loves her kids… who are the products of her incestuous adultery with her twin brother, which also led to the crippling of Bran Stark." By the time you get to the end of that thought, you're probably back to thinking of them as villains.
Even Tyrion kind of agrees, noting that his sister Cersei might be cunning, but is too proud; and that for all his skill with a sword, Jaime is still too impulsive (39 Tyrion 5.47).
So, basically, Cersei and Jaime are monsters. ("Cersei" even sounds like "Circe," a not-so-nice sorceress from Greek mythology.)
There is maybe one area where Jaime seems less like a monster than Cersei, and that's in the way he treats his brother. Cersei doesn't get along with Tyrion and maybe kind of hates him, but Jaime is the only family member who treats Tyrion with any affection (10 Tyrion 1.33). So does that make us like him more since we generally like Tyrion? Can Jaime be redeemed?
Cersei's three kids are actually her kids with Jaime, which is why they're all blond. (If they were Robert's, they'd have dark hair, like the rest of the Baratheon kids. Note: Do not learn about genetics from this book. This is not the way it actually works. Probably their hair-color is somehow magical.)
Myrcella is a young girl (not quite eight) and Tommen is a super young, sweet-natured boy. Those two are not particularly interesting to this story right now.
But Joffrey is a different story, since he's very important to the plot. After all, it's Joffrey who (stubbornly and cruelly) orders Eddard Stark to be decapitated. And he's the one who makes sure that Sansa sees the decapitated heads (68 Sansa 6), which is just ridiculously monstrous. When it comes down to it, this is the monster that makes it impossible for the Lannisters to make peace with the Starks.
One of the pleasures of this book is watching Sansa realize what a terrible person Joffrey is. Someone can look and even act nice one moment, but really have some amazing depths of cruelty. We spend most of the book hoping that Joff will get the Viserys treatment. But Joffrey both survives and even prospers in this book, rising from Prince to King. That's not justice, but, of course, since this is a George R.R. Martin book, it's not always certain that justice will prevail. (Check out our theme discussion about "Justice" for more on that.)
Tyrek and Lancel Lannister are Cersei's much younger cousins who serve as King Robert's squires. (Tyrek is Ser Tygett Lannister's son and Lancel is Ser Kevan Lannister's son.) They show up in this book to remind us that Robert is in danger because he's surrounded by Lannisters. And, in fact, Lancel is probably more than a little responsible for King Robert's death since he makes sure that Robert is drunk when he goes out hunting (48 Eddard 13.67).