Sebastian "Bash" de Poitiers (French: Sébastien) is one of the male leads of Reign. He is the illegitimite son of the King of France, and his favorite mistress Diane de Poitiers. He is also the half-brother to Francis II, the next in line to the throne and the half-brother to Elizabeth, Claude, Charles and Henry Jr.. Despite this, he is still his father's favorite. After a prophecy that predicts Francis' death if he were to wed Mary. The process of legitimizing Bash for him to become the heir, next King of France and husband to Mary begins. When Francis returned to the French Court, Mary chose to be with Francis and Bash lost the right to the throne. He is portrayed by the Canadian actor, Torrance Coombs.
In the Pilot, Sebastian is first seen before Mary's arrival in court, where he jokes with his half- brother Francis questioning on which girl he had been with. When Francis calls him the "lucky bastard", Bash smirks. Later on he is seen attending the ceremony for Mary's return to court with the rest of his family.
When Mary's dog Stirling runs into the woods, he warns her that young girls, royals, queens don't leave the castle alone and that she should let it go, strongly emphasizing that she should not enter the woods surrounding the castle. After proceeding to tease her about her life with the nuns, she replies that he is cheeky. He promises her that he will find her dog.
At his half-sister's wedding he and Mary glance at each other when the girls are all dancing, which bothered Francis. When he later runs into Mary to return Stirling to her possesion, he comforts her and assures her that she isn't alone and that he isn't talking about her friends. But when he sees his mother at the end of the hall, he quickly changes his statement. After Mary has left, his mother asks him where he found the dog, he replies in the woods. His mother then asks him, with a worried look on her face, how close he got.
"Take care my brave son, or you will bleed for a girl who will never be yours" -Diane de Poitiers to Sebastian.
In Snakes in the Garden, Mary tells Sebastian of her worries about Colin. He says he knows a way out of the castle and will try to track Colin for her. He also makes her aware that the guards are afraid of the woods, so he will look there as well. He mentions that these are dark and dangerous times, but Mary’s presence brings light.
Sebastian, searching in the woods for Colin, comes across blood on branches and continues to follow the trail. Blood is seen dripping on both white petals on the ground and onto Sebastian’s face. He looks up, and there is a body strung from the tree by its ankle. Sebastian hears someone approaching when he is getting the body situated to bring back to the castle. He hides, taking out a knife, but realizes it is Francis. He questions how Francis found him, and Francis says that it was Sebastian who taught Francis how to track. They hear people in the woods around them, and while Francis thinks it is guards who will not hurt them, Sebastian knows the truth. Sebastian calls out “We take what’s ours, not yours. Even dead men answer to the king.” He calls out in another language, "Lumenick dushkader et sprago faraha. Ay raynim doluchtai." while cutting his hand and bleeding onto the white petals on the ground. He tells Francis that the people are leaving and they need to get Colin’s body back to the castle. Later, Francis confronts Bash about going out into the woods on Mary's command and the latter mentions that he feels as if it's his duty to protect her, though Francis doesn't believe that was the reason for a second.
In Kissed, Bash and Henry are sparring and the former gets defeated when it's obvious his mind is now on the enemy in front of him. Francis arrives in hopes of talking to his father about helping Scotland and explains that he thinks they're trying to poke France to see the reaction; if France acts quickly and harshly, it might scare them off from trying anything else. Henry again says that he has made up his mind and Francis challenges him - if Henry wins a sparring match, Francis will shut up about the matter. If Francis wins, Henry sends the men. Francis ends up winning and yet, Henry refuses to honor the agreement, stating that making promises to everybody and then acting your own way is all a part of being king. Francis then tells Bash he does not need another lesson.
That night when King Henry allows Francis to send troops, Bash leads them. He returns from battle gravely injured, as he reveals that the English rode from Calais and slaughtered the six companies of men that Henry sent for Mary. Nostradamus, whose vision is confirmed by the carnage, decides to concoct a potion to put him to sleep.
In Hearts and Minds, Still recovering from his injuries and being tended to by Nostradamus. Bash is visited by Lola who was checking on him on Mary's behalf. Where she then reads him Norse Mythology. In fear of Mary's safety from Tomás Francis confides in Bash of the rumours of him murdering his first wife. Knowing there was no proof they decide to find some. Tomás walks in on their conversation and tells Francis to stay away from Mary, when Francis threatens him but Bash stops him before he does something regrettable and falls in pain from his wound. When Tomás leaves Bash tells francis that "He is a monster and whatever the pope chooses to call him, if you don't kill him I will".
Later at the festivities he is approached by Lola who was dressed as the Norsse God from the book she read him. When Francis joins them and they begin talking of Tomás and how he was desperate to get a queen. That he was lucky Bash was ambushed they realised that he was the spy who informed the English of France's troups approaching. Bash and Francis then ride out to the woods to find Miguel to gather information that Tomás is guilty. Bash and Tomás fight which leads to him being in pain due to his injuries and Francis steps in to help him. When Francis kills Tomás Bash reasures him that "Killing wasn't supposed to be easy, if your hands weren't shaking you'd be him". He lastly watches Simon Westbrook being released home thanks to the evidence he, Francis and Mary found.
In A Chill in the Air, at the Harvest Festival, Sebastian says hello to each of the ladies in turn and asking Mary what has changed to make her seem to enjoy her time in France for once, saying her smile is like the sun. She asks if he enjoys flirting with everyone, and he agrees that he does in fact flirt with everyone. Mary tells him that without the burden of worrying about an attempt on her life, she is quite happy. When he asks if there is anything else, Mary confesses that Francis also makes her happy which makes Sebastian leave, telling her he wishes to be drunk at her wedding. Francis shows Mary a boat he made for her, which he named Mary. Someone approaches them and tells Francis that the guards found a girl roaming the woods near the castle. Her carriage was overrun by bandits and when she was found she started asking for Francis. Francis goes to Olivia, who tells him that her servant was killed and she was afraid. Sebastian takes Francis’ place at Mary’s side and Mary asks him about the girl. Sebastian tells her that Olivia used to live at court and left a few months before Mary arrived. He also tells her that Francis was brokenhearted when she left. They watch as Francis escorts Olivia from the area and to the castle.
Francis finds Sebastian on horseback and asks what he told Mary about Olivia. Sebastian says that Mary was only informed of Olivia being Francis’ first, but didn’t mention of how many. Seeing Francis upset, he apologizes for overstepping his bounds. Francis then tells him that he believes Olivia’s carriage was overrun by pagans and that they were told the king’s road was flooded, which it isn’t.
Guards find Olivia’s carriage in the woods and sees that the wheel was broken due to a trap placed. They find the driver and the servant hung upside down with their throats slashed and blood dripping onto the earth beneath them. Sebastian rides up to them and notices that the driver is still breathing and wants to cut him down. The guards disagree, saying Sebastian is interfering with a ritual and the people who did it might come after him. Nostradamus is tending to the driver and asks about the people in the woods, asking if they were close. He calls Sebastian a fool for interrupting their sacrifice, but Sebastian thought the people only sacrificed animals. Nostradamus says they have always done human sacrifices, but haven’t been as bold as they are now, luring people into the woods for the sacrifice. Neither know what has changed, but Nostradamus does know that Sebastian is in danger for interrupting the sacrifice and that he needs to stay close to the castle in the coming days.
Nostradamus interrupts Sebastian’s conversation with 2 women, telling him that the driver of Olivia’s carriage has died. He tells Sebastian of the conversation he had with the man before he passed, mentioning the pagans need of sacrifices. Apparently they need fresh human blood as a sacrifice for a beast that lives within a cave in the woods, the location of which only a few people know. Mary finds Sebastian on the lakeside, drinking from a casks of wine. She asks for some, not liking the taste but continues to drink from it. He says he should tell her to slow down, but she knows he won’t. A clearly drunk Mary is complaining to Sebastian. She tells him that she was foolish to ever think they could be anything but royals in an arranged marriage, which would imply either would be able to walk away from their situation. Mary is angry that Francis could do whatever he wants while she has to wait for him. She stops ranting, asking Sebastian if she is overreacting and boring him. He tells her he doesn’t understand why Francis would look elsewhere if he has Mary. Mary kisses Bash and pulls back, apologizing and telling him she should not have kissed him. He agrees, telling her he should have kissed her first. When they finally pull away from each other, Francis is in the background. He obviously saw them kiss and walks away. Mary tells Sebastian that they should not have kissed, that it was a mistake and that she was angry.
Sebastian is knocking the dirt out of his boots when the pagan from the road and the kitchen, with the necklace that made the indent in his chest, tells him that he has taken something that doesn’t belong to him. The man tells Sebastian that it wasn’t the first time he has stolen from them, and Sebastian remembers cutting down Colin’s body. He tells Sebastian that he wasn’t his to save, calling him by his name. He also says that his life means nothing now, that he has been seen and that his death will be for something greater. He tells Sebastian that he needs to pick another sacrifice from the castle, and if he doesn’t they will chose one for him. He then throws his body from the ledge, which is not on the first floor, and Sebastian looks over.
In Chosen, Sebastian had to choose someone to sacrifice to the pagans and when he didn’t – they chose for him. They picked Mary to be their sacrificial lamb and they let her know by managing to put a necklace right on her pillow while she was sleeping. She knows it wasn’t Francis. After all she knows Francis is angry at her and doesn’t know why. She thought Sebastian must have been the one to leave the necklace. She asks him as they all begin to crowd. He says it wasn’t him although he does recognize the symbol. Sebastian pulled Mary and Francis alone to a meeting. He had to tell them what the necklace meant. Now that Francis knows Mary is being targeted he issues more body guards for her. Yet it was the way he issued his command that alerts Sebastian into wondering why his brother is so angry. Francis says there are too many secrets between them. A part of him refuses to say what truly is bothering him out loud. He can’t say he saw Mary in Bash’s arms.
Bash has a former pagan to help him understand this sacrifice practice. His mother used to be a part of the pagans in the woods. She left once they began to change their ideology. Because of her involvement, the pagans might even count Bash as one of them. She warns her son though. Mary belongs to Francis at whose will; he’ll eventually be allowed to stay at court. He shouldn’t forget that. Bash used his influence and money to pay for a prisoner out of the dungeon. Francis knows she’s going to use the prisoner as a sacrifice. He told Mary Bash’s plan. She was horrified and it came to her why the pagans would have thought she was important to Bash. She was going to tell Francis when he stops her. He admits he saw her with his brother. It’s why he was angry. After all he told her about putting their position first and thinking things through; she ignored him. That’s why his brother is forced into killing someone.
Bash took his prisoner to the Blood Wood. He didn’t want to kill the man. It’s why he killed one of the pagans instead. He was walking taking the prisoner back to the castle when the foolish man admitted he heard him fight with the pagan. He knows Diane was once a pagan. Bash had to kill him. He couldn’t let any stories about his mother float around. Bash doesn’t reveal what really happened to Francis and Mary. He only tells them the debt has been paid. Francis is relieved but he lets them know. Nothing can ever happen between them again. He shouldn’t have let his feelings come into this. So for the time being she can spend her time with others and so will he. Only Bash is off limits and because he will be king, Bash shouldn’t take what he said as a request.
Bash took the threat to his life seriously. He went to his mother and told her they aren’t safe here anymore. His mother promises he will be remembered. She won’t allow anyone to forget her son.
In Left Behind, Bash didn’t go off to fight with his father because, as he tells his mother, he’s had enough killing for a while. Diane doesn’t want to talk about her son’s recent lethal adventures, though, she wants to talk about making him king. When Henry dies Diane is sure Catherine will throw her out and Bash will live only by his brother’s mercy, but those problems will be solved if Bash somehow becomes the legitimate heir to the throne. Bash warns his mother that that sort of talk can get mistresses and bastard sons killed. Diane is still talking about bribing cardinals to get Bash legitimized, but he tries to shut her down by saying that stealing the throne from his brother isn’t something he’s going to do. She tries to say that Francis is the one that stole it from Bash, since Bash is older, but Bash is having none of it. He’s happy as he is. The conversation is cut off when Italians burst into the room to capture them.
An Italian guard brings Bash some food, and Bash tries to take the opportunity to free himself. He quickly runs into more guards, though. Later, Bash is locked up better now, and a guard comes to tell him that the count wants anyone who defies his authority killed. Bash braces himself for an attack, but instead he’s given water. Diane is paying the guard to look after him.
The next morning, Bash walks with his mother outside and suggests that she played a role in arranging for the castle to be taken. If something happened to Francis and the younger boys then Bash would be the only person left to succeed their father. The Vatican would be willing to legitimize him, and he’d even be able to wed Mary. Diane admits her role, and says that Bash was supposed to be gone with his father so he’d never know. The knowledge that his mother wanted to have his brother’s killed behind his back, rather than with his knowing, does not comfort Bash who calls his mother’s plans poison. This is his family she wants to sabotage. Except, she says it’s not. He’s not really their brother, and Catherine would kill him if she could get away with it. Bash just gives her a hard look and walks away.
In Fated, He goes in to the hallway to talk with his mother about him being legitimised. Asking her if the cardinals visit to the castle has anything to do with her, she informs him that matters as such are discussed in private. He tells her again that he does not want to become king, she replies by telling him that it would mean he could Marry Mary. He still declined, saying it was no way to win a woman. After the announcement in the throne room he and Diane again discuss the topic. She tells him that the church will not be able to support it, but he see's it as a good thing. She tells him that he can't want Mary not even in secret or in his heart because Francis will know. When Mary goes to talk to Bash trying to decipher Nostradamus' prophecy. Where Bash tells her that because he is a bastard he was able to choose the lion as his own symbol. When he next talks to his mother she tells him that Catherine knows about Diane's plans to legitimise Bash. Because of this news he would have to leave the castle for a while until she can make Henry understand. When he was preparing to leave court he runs into Mary and they leave the castle together as Francis and a guard watches.
Bash and Mary are still on the run from the soliders in For King and Country. Bash sees no other option but to jump off the cliff into the unknown waters to escape. England is at stake and the King won't let Mary get away. Mary is at first reluctant to jump off the cliff, as she thinks they cannot survive. The King's men soon surrounded them. Bash and Mary hold hands and jump in the water. Mary and Bash have found a place to stay in an inn. Bash tells Mary he is sure that Queen Catherine has found out about his mother's plot to legitimise him. Otherwise, Bash's mother is not someone who will turn her back on King Henry. Mary knows that Bash does not want France and it is possible that people might think worse of him. Bash says that Francis is already thinking worse of him. There is a knock at the doors. Bash tells Mary to hide under the bed. The King's men come inside and threaten Bash, but he does not tell them about Mary. When they threaten to cut off his fingers, Mary comes out. The two are taken back to castle. At the castle, Bash asks Mary to be strong, as the men take him away to the dungeon.
King Henry has eyes only on the throne of England. He is ready to sacrifice his son for that. If Mary does not marry Francis, Bash's life is in danger. King Henry tells Mary that she and Francis must get married and together lay claim to the throne of England. If she does not do that, Bash will be charged with treason and executed.
Francis visits Bash's prison cell and punches Bash. He beats him up, demanding to know why he stole Mary. Mary comes and stops Francis. She tells him that Bash knows nothing about her proposal. It is her decision. Francis tells Mary that she is throwing everything away for superstition. He is not going to forgive her even if she is doing everything to save his life. Bash is bitter and hurt, as he has never wanted his brother's crown. Mary wants to know if he will accept the throne to save his brother. He says: "I've more than a half-beat to think about it."
The King of France agrees to Mary's terms. Bash ascension to the throne will be announced once Rome legitimizes him. Bash and Francis have one last talk. Francis tells Bash how he has taken the throne and Mary from him. Now Francis has his freedom. Bash realizes that he has lost his brother/best friend.
Bash and Mary have their talk. One moment, Bash was on the clopping block and the next he gets the crown. They both are doing everything to save the life of Francis. Bash says that it was unexpected that he was getting married to her.
In Sacrifice, The episode opens with a sword fight between Bash and one of the guards. The guard out-maneuver's Bash. He tells Bash to learn to expect the blade that can't be seen. Otherwise, it will be the last thing that he ever learns. Bash introduces the guard to Mary, as his new bodyguard, Alec, sent by his mother. Mary wants to know why Bash is not present in the throne room, as everyone is expecting him to be there. Bash has to show to the noble-men that he can become a capable King of France. Bash believes that at the throne room, the noble-men are waiting for his fall, as a bastard's succession to the throne threatens their line of succession. Mary convinces him to be at the throne room. There, Bash is bored to death, listening to mundane complaints. He is not too amused listening to chickens and goat feud. When Lord Hugo asks him to resolve the feud, Bash comes-up with some silly ideas. However, he is fully awake when a pregnant, young woman is brought in. She is accused of stealing. Bash is a little rattled but soon composes himself, ordering girl's home to be searched and incarcerating the girl in the castle.
Once the young girl taken away, a woman arrives, approving the bastard as the King. She takes some steps forward to meet the King when Alec brings her down. She is holding a small knife, which has been dipped in poison. It was an attempt to kill Bash. Mary finds Bash with the young, pregnant woman. She doubts that the girl might be pregnant, with Bash's child. Bash tells Mary that the young woman is his cousin, Isobel, daughter of his mother's half-brother. Isobel is not pregnant with his child but Catherine thinks so. The child's father passed-away in an accident. Isobel's father was accused of treason and as a result, he was beheaded for his crime. If anyone finds a connection between Bash and Isabella, and that a traitor was his uncle, Bash cannot be the King. If the real identity of Isobel's father is discovered, she will be tortured and might reveal her connection to Bash, which is worse than what they doubt -- Bash and Isobel are lovers. Mary decides to help Bash. Isobel is showing signs of going into labor. Mary and Bash form a plan to fool Catherine's guards and help Isobel escape her condemned fate. Mary accompanies Isobel in a carriage, while Bash takes another route.
Bash meets Mary, Isobel and Alec at a spot inside the forest area. Isobel's water has broken, which stops their movement out of the woods to a safe haven for the young woman. They pitch a tent inside the forest area and keep a watch. It is pitch dark outside the tent. When Mary steps out to bring water, she finds a marking of pagan, which alludes to the mark of death. She breaks down a pagan structure. When Bash and Alec learn about what she has done, they are hyper. Mary tells them that pagans would have killed them if she had not done that. Pagans soon surround the tent, chanting a hymn. Bash, Alec, and Isobel hum the same hymn, and soon the pagans leave. They do not leave before beheading a horse. Mary is furious as she believes Bash is a pagan and a heretic, and it is the truth that he was hiding from her. Mary's absolute hate for pagans surfaces. Bash tells her that he is a catholic but knows the hymn because of visiting his uncle's place as a child. Isabella, her father and Alec are pagans, and Isobel's father was beheaded because he found out to be one.
Isobel gives birth to a girl. However, she soon passes away because her bleeding does not stop. Before dying, Isobel asks Bash to take care of her daughter like he took care of her. Bash promises to do so. He gives the baby to a woman, asking her to take proper of the motherless child. Mary notices a mark on one foot's sole. Bash tells her that it is a pagan custom and Isobel must have done that but the mark may disappear. Bash and Mary return to the castle, with Isobel's body. Bash tells Lord Hugo he had to kill Isabella because she attacked him. He feigns ignorance about the missing baby. Lord Hugo has no other option but buy that explanation.
On Isobel's grave, as per Pagan's custom, Bash cuts his hand and drops blood. Mary does the same. Bash tells her that he never wanted the crown. But if that is his fate, he will accept it and learn to wear it. However, Bash says that she needs to know that he is not Francis, and his "duty will never be to some country, some land, or some throne." He adds that if he marries Mary, she will become his family and he will do it for her and only for her.
In The Consummation, Bash is seen with Mary Stuart they have a talk and then kiss. They know its their wedding date and Bash is very excited for the wedding to occur. When Bash finds out that Mary and Francis can wed he is heartbroken. When Bash goes outside he and Francis have a fight for Mary but is stopped by Mary. At last Mary and Francis' wedding occurs and Bash doesn't attend it because he is still heartbroken. To make situations worse Henri makes Bash watch the couples Consummation. It is soon known that Henri is making Bash leave the French Court.
In Monsters, Francis finds out that Bash is back at France. When arrived Bash is at Mary and Francis' room he told them about The Darkness and how it injured Olivia. After knowing about The Darkness the brothers go out to fight it. Francis is still mad at Bash but soon changes when Bash saved Francis' life. The two rekindle their relationship back to the French Court. After coming back Francis tries to find out who wanted his execution. He soon comes to know that their father wanted to. Francis tries to make the King and Bash come closer but soon ends up getting worse when he makes Bash and Kenna forcefully wed.
In Liege Lord, Bash and Kenna make an agreement back at their room. He tells her that he will try to love her and they need to get closer leading up to their agreement. Meanwhile Mary seeks help from Bash after knowing about the French-Scottish agreement. When Kenna finds out she starts to cry but Bash tries to calm her down.
He is warm and comforting toward people he cares about or even people he's recently met, as he is always comforting Marie and helping his half-brother Francis. He also shows kindness to people he doesn't know well like the kindness shown to Lola in Hearts and Minds. He has a weary relationship with his half-brother Francis, but he always manages to Always have Francis' back. He also cares deeply for Mary but knows he can never have her as she is Francis' fiancée (now wife). He is quite humurous, often poking fun or making jokes; Mary described him as being cheeky yet he is capable of being serious if he wanted. He is very confident in himself and his abilities.
Sebastian is "gorgeous" as mentioned by Kenna in the Pilot episode, and he has shaggy, straight, dark brown hair and bright blue eyes. He has a round-shaped face with a pale skin tone, and he is tall and slim. As for facial hair, he usually has stubble and is not always fresh and proper.
He has worn different types of clothing appropriate for the time period. After becoming legitimized, he dresses as a member of higher class with fancier clothing. He used to dress more casual by wearing a loose shirt instead of an intricate jacket.
He is the only main character not based on a real person.
King Henry II only acknowledged one male illegitimate son who was only given a small title, due to the fact that at the time it was considered foolish to do so for it encouraged successions wars. (See Henry for more details.)
He was engaged to Mary until she decided to marry Francis.
In Left Behind his mother planned to legitmize him and used Mary as an influence to make him agree.
There are internet rumors Bash is based on Bastian Pagez, one of Mary's most loyal servants. This is not true.
His cousin Isobel is a pagan along with his mother.