Cersei Lannister is one of the evilest characters on Game of Thrones, but it's hard not to admire her determination. In a world in which women are treated as second-class citizens and there are deadly obstacles around every turn, Cersei managed to outlive most people and briefly sit on the Iron Throne.
However, even with all she achieved, Cersei was capable of making some bad decisions. Her need for vengeance and power often steered her into bad situations and it ultimately meant the end of her. Here are some of Cersei Lannister's biggest mistakes on Game of Thrones.
Having Sex With Jaime At Winterfell
Perhaps the thing that kicked off all the mayhem of the show was Bran seeing Jaime and Cersei having sex while visiting Winterfell. Trying to keep their incestuous affair a secret, Jaime throws Bran out the window and the war between the Lannisters and Starks began.
All of this because of such a reckless act between Jaime and Cersei. Anyone could have found them and probably could have gone a lot worse.
Making An Enemy Of Tyrion
Though she loves her brother Jaime in a very inappropriate way, Cersei despises her brother Tyrion with all her heart. Tyrion is used to being treated badly by his family, but it seems like he would rather get along with his sister if given the chance.
Cersei decides to hold on to her hatred for Tyrion for no good reason and make an enemy of him. Cersei has plenty of enemies, but Tyrion is too smart and resourceful for her. If she had made him an ally, she probably would have achieved much more.
Trusting The Tyrells
Trust is not something Cersei is known for and it's unlikely she really trusted anyone in her life. However, in an attempt to align the Lannisters with a powerful family, Cersei did allow the Tyrells to get close to her family and for Margaery to marry Joffrey.
Cersei was arrogant to think that the Tyrells would allow the Lannisters to hold the power in their relationship. This resulted in Joffrey's assassination at the hands of Olenna Tyrell and a feud that almost destroyed King's Landing.
Killing Robert Baratheon
Cersei's marriage to Robert Baratheon was far from a fairy tale marriage. By the end, they outright hated each other and their children were actually the product of incest between Cersei and Jaime. So it's not surprising that Cersei eventually had Robert killed.
Cersei must have felt backed into a corner since Ned Stark threatened to expose the truth about her children. But it would have been much easier to kill Ned than Robert. Robert was the perfect puppet king but killing him led to chaos and fighting for the throne.
Sleeping With Lancel
It appears Cersei has a certain type when it comes to men. When her usual lover, Jaime, is away in battle, Cersei decides to start sleeping with her pathetic cousin Lancel Lannister.
Obviously, this relationship is a bad idea for a number of reasons, but Cersei probably didn't know how badly she would regret it in the end. Lancel eventually becomes a religious fanatic and tells the High Sparrow about their affair, leading to Cersei's arrest.
Not Protecting Tommen
Cersei often claims to do most of her acts of evil to protect her children. However, sometimes it seems like being evil is more important to her than those children. After losing all of her power to the High Sparrow, Cersei enacts a horrific revenge plot, blowing up all of her enemies with wildfire.
Though she ensures Tommen is not present during the attack, she fails to realize how devastating this would be for him. As she is busy torturing Septon Unella, Tommen removes his crown and jumps out the window.
Killing Missandei
Revenge seems to be a huge passion for Cersei and she's very good at achieving it. But her quest for vengeance is often misguided and causes more trouble for her than its worth.
After managing to capture Missandei, Daenerys' closest friend, Cersei and Daenerys meet for one final parlay before Daenerys attacks King's Landing. Knowing what she is up against, this is Cersei's final chance to save herself. Instead, she has Missandei executed, which ensures Daenerys will burn King's Landing to the ground.
Going Back On Her Deal With Daenerys
With the Night King and his army about to invade Westeros, Jon Snow assumes that this is the one enemy that will bring the entire kingdom together. As it turns out, he assumed wrong.
Cersei pretends to care about the threat of the Night King but instead uses this as an opportunity to push back against Daenerys' army. This is a movie that finally causes Jaime to leave her and for her to become the most hated person in Westeros.
Giving The High Sparrow Power
When Margaery marries Tommen, Cersei begins to see that she could be outmaneuvered by the new queen. In an effort to stop Margaery's rise to power, she gives power to the High Sparrow, a religious leader.
He begins arresting those who have sinned, including Margaery and her brother. Unfortunately, Cersei just managed to create a new enemy as the High Sparrow soon has her arrested as well. Cersei is humiliated and degraded like never before.
Making Joffrey King
The one goal on Cersei's mind was seeing a Lannister sit on the Iron Thrones and rule Westeros. Unfortunately, the first Lannister that sits on the throne is Joffrey and she soon lives to regret that choice.
Joffrey immediately makes the situation worse by executing Ned Stark and starting a war. In her quest for power, Cersei failed to consider how dangerous Joffrey would be as king. Making such a terrible person king probably ended up being the downfall of the Lannisters.