Arthur and Guinevere

"Just... Live for me, Arthur, that's all I ask right now."

- Gwen to Arthur Arthur and Guinevere were friends and love interests. They cared very little for one another at the start of the series, as Gwen believed Arthur to be an arrogant bully and Arthur barely seemed to be aware that Gwen existed. As time went on, however, they grew to be friends and eventually fell in love. Though their courtship was complicated by their differing social classes (and later by interference from Morgana), they were ultimately married in the final episode of series 4.

First Impressions
"Who'd want to marry Arthur?"

- Gwen to Merlin

There was little interaction between Arthur and Guinevere at the start of the series, mostly because their differing social classes gave them no reason to do so. Gwen was known to have a rather low opinion of Arthur at this time. She believed him to be an arrogant bully, and couldn't imagine anyone wanting to marry him (The Dragon's Call).

Arthur, on the other hand, had no discernible opinion on Gwen at all and treated her no differently than he would any other average citizen. When her father mysteriously recovered from a plague that nobody else had survived, Arthur thought nothing of searching her house and, after discovering a magic poultice beneath her father's pillow, did not hesitate to arrest her.

That said, Arthur was a fair man who had no wish to see someone executed for a crime they didn't commit. So when Uther sentenced Gwen to death for not only the poultice but also for creating the plague, Arthur helped Morgana defend her. He pointed out that being guilty of one crime did not make her guilty of both and said that he didn't believe that there was evil in her heart. He later accompanied Merlin and Morgana to the underground reservoir and killed the Afanc that was contaminating the water supply, thus proving that Gwen was not responsible for the plague (The Mark of Nimueh).

Becoming Friends
"We'll be fine." "How can you be so sure?" "Because I have faith in you. I mean... We all do."

- Gwen and Arthur

Gwen and Arthur began to grow closer when they helped to defend the village of Ealdor from bandits. Arthur took charge as soon as they arrived in the village, coming up with a strategy and teaching the men to fight. The villagers were greatly inexperienced when it came to combat, however, and Gwen and Morgana were concerned that there weren't enough men to hold off Kanen's forces. They tried to talk Arthur into letting the women fight as well, but Arthur dismissed their idea, as he believed it to be too dangerous.

Undaunted, Gwen brought the matter up again when Arthur was addressing the villagers the night before the battle. She said that the women had as much right to fight for their lives as anyone, and when Arthur pointed out that the women didn't know how to fight, she stood her ground and said that there was strength in numbers, and that the villagers would stand a better chance with everyone pitching in against the bandits. Recognizing the truth of her words, Arthur agreed that the women had every right to help defend their homes, and said that he would be honored to fight alongside them if they chose to do so.

The next morning, Gwen brought Arthur a bowl of food to eat while he was standing watch in the woods. Though he thanked her for doing so, he was clearly not pleased with the quality of the fare, and Gwen (fed up with his snobby behavior and offended on Hunith's behalf) lost her temper. She snapped that food was scarce for the villagers and that he shouldn't turn his nose up at it. Then, horrified at having spoken in such a way to the prince, she quickly apologized and made to leave. Arthur, however, was not offended by her rebuke, and in fact thanked her for it. He also told her that she was right to speak up about the women fighting, as they would need all the help they could get. Sensing his unease about the coming battle, Gwen awkwardly tried to reassure him that they would be fine and told him that she had faith in him, which Arthur appreciated (The Moment of Truth).

When Gwen's father was killed while trying to escape from prison, Arthur personally ensured that her job was safe and that her home would be hers for life. He also assured her that if there was anything she wanted or needed, all she had to do was ask, and said that he was sorry for what had happened. Gwen was stunned and deeply touched by the gesture, to the point where she could barely find her voice to thank him (To Kill the King).

Gwen later helped care for Arthur when he was bitten by the Questing Beast. Though Gaius was certain that (barring a miracle) the prince was going to die, Gwen refused to give up hope. As she sat his bedside, she told him that she knew he would someday be a great king, greater than his father could ever be, and that he would create a Camelot that was just and fair and would make the people proud to call him their sovereign.

Later, after Merlin returned from the Isle of the Blessed with a cure for the Beast's poison, Gwen was overjoyed by the prince's recovery but mortified when she realized that Arthur had been conscious enough to hear her musings. Flustered by his teasing, Gwen denied having said any of it and quickly fled from the room, leaving Arthur amused (Le Morte d'Arthur).

By the time of Cornelius Sigan's attack on Camelot, Gwen and Arthur had grown noticeably closer. When Arthur was injured fighting the sorcerer's animated gargoyles, Gwen risked her life to go looking for him and saved his life twice before escorting him inside to tend to his wounds. Surprised, but grateful for her actions, Arthur clumsily complimented her bravery and thanked her, which left Gwen flustered (The Curse of Cornelius Sigan).

Falling in Love
"I know I have much to learn. There are some things that I am terrible at - cooking being one of them. But also, knowing what to say to someone I care about."

- Arthur to Gwen

When Arthur sought to prove that he could win Camelot's annual jousting tournament without being given special treatment, he disguised himself as a civilian and entered the tournament as Sir William of Deira. Gwen allowed him to stay in her home during this time, (presumably because Merlin asked her to). Though she appeared to be a bit apprehensive about him staying with her at first, she respected Arthur's desire to prove himself without the aid of his title and did what she could to offer support.

It wasn't long, however, before Gwen became fed up with her guest's rude and arrogant behavior. The prince was little help around the house, treating her like a servant and unknowingly commandeering her bed, which forced her to sleep on the floor. When Arthur finally discovered the arrangement and tactlessly remarked that she should have said something, Gwen exploded into a rant about how rude he'd been. She told him that his effort to prove that titles didn't matter meant nothing if he continued to act as though other people were beneath him.

Having realized how appalling his behavior had been, Arthur apologized and offered to cook dinner as a peace offering. Though obviously skeptical about the prince's culinary skills, Gwen accepted his offer and went out for a walk. She returned that evening to find Arthur and two perfectly cooked dinners waiting for her. The two shared a pleasant meal together, but things quickly took a turn for the worse when Gwen noticed that the plates bore the royal seal and realized that Arthur had procured the dinners from the palace kitchens. Furious that Arthur had lied to her and upset because she though that he'd finally learnt some humility, Gwen told the prince that a good king should respect his people, no matter who they were. Recognizing the point she was trying to make, Arthur apologized once more, and admitted that he often didn't know what to say to people he cared about, which seemed to appease some of Gwen's anger.

Moment later, Merlin arrived and informed them that there was an assassin in Camelot looking for Arthur. Gwen allowed the prince to continue living in her home despite the threat, and offered to let him keep using her bed so he would be well rested for the tournament. Arthur, however, (having learnt his lesson) insisted on taking his turn on the floor. The next morning, though things were still somewhat awkward between the two, Gwen offered the prince a handkerchief to wear as a good luck token during his match. Touched, Arthur not only accepted it, but thanked her with a kiss.

After Arthur was injured while jousting against the assassin, Gwen helped tend to his wound and tried to talk him into forfeiting the match. She told him that he didn't need to prove anything, least of all to her, but Arthur responded that he had everything to prove to himself and went on with the match. Later, after being declared the winner of the tournament, Arthur chose to send the farmer he'd hired to pose as Sir William to collect the trophy in his place, thus maintaining their deception. His decision surprised Guinevere, as Arthur had repeatedly voiced his desire to unmask himself at the tournament's end and enjoy his moment of glory, but the prince merely replied that perhaps this was a time for humility. They later stood together at the back of the crowd and watched the supposed knight accept his reward with laughter and smiles.

Arthur made his public return to Camelot shortly after the tournament's end. After reporting to his father, he caught up with Gwen in a castle corridor and tried to address what had happened between them, reluctantly concluding that his father would never understand it. Having already accepted that a relationship between them would be impossible, Gwen told him that he didn't have to explain, and said that perhaps when he was king, things would be different (The Once and Future Queen).

Denial
"Because nothing can ever happen between us! To admit my feelings knowing that... hurts too much."

- Arthur to Merlin about Gwen

When Gwen was held hostage by the bandit Hengist, (who believed her to the Lady Morgana), Arthur disobeyed his father's orders to do nothing and snuck out of the city with Merlin to rescue her. The prince was unusually impatient and reckless in their endeavour, which puzzled Merlin until he figured out that Arthur had developed feelings for Gwen. He appeared to be both delighted and amused by this, and wasted no time in teasing Arthur about it.

The subject quickly grew more serious, however, when Merlin's joking challenge for Arthur to admit his feelings resulted not in mutual teasing but in a frustrated confession from the prince that revealed not only the depth of his feelings for Gwen but how much he'd been struggling with the idea that nothing could ever happen between them. He lamented that his father wouldn't even let him rescue a servant, much less marry one, to which Merlin pointed out that Arthur could change that when he was king. Dejected, Arthur countered that he couldn't expect Gwen to wait for him, but Merlin assured him that if Gwen felt the way he did, she would wait for him, which seemed to give Arthur hope.

It didn't take long, however, for that hope to come crashing down. Merlin and Arthur arrived at the bandit's hideout to find not only Gwen but Lancelot, who had been captured while trying to help her escape earlier that day. As the group escaped the fortress through the tunnels, Arthur caught Gwen and Lancelot holding hands and sharing a meaningful glance. Heartbroken, he covered up his feelings (and perhaps tried to salvage a bit of his pride) by claiming that he'd only come after Gwen because Morgana begged him, which offended Gwen and didn't fool Lancelot for a minute. He soon learned the truth of the matter from Merlin and resolved to leave during the night so as not to come between the two, leaving Gwen devastated. Though clearly pained by how affected Gwen was by Lancelot's departure, Arthur ultimately chose not to intrude on her grief and kept his hurt feelings to himself. They returned to Camelot in silence, leaving the matter undiscussed (Lancelot and Guinevere).

When Uther was bewitched to marry a troll disguised as the Lady Catrina, he ordered a new tax on the people forcing them to pay for the protection that Camelot provided. Arthur was against the tax, pointing out that most of the people were poor and barely getting by as it was, but his father (firmly under Catrina's control) ignored him. Later, when Arthur came across a man being arrested because he couldn't afford to pay the tax, he ordered the man released and all the money redistributed to the people. The people were deeply grateful for his actions, Guinevere included, though Arthur had not seen her in the crowd.

Gwen later visited the prince and commended him on his actions. Arthur, who had gotten into a fierce argument with his father over the incident, was grateful for her praise but lamented that his father was going to keep imposing the tax in spite of his protests. Gwen hastened to assure him that the people knew that he'd tried and wouldn't forget what he'd done for them, but Arthur continued to muse that perhaps his father was right in saying that he couldn't be a friend to the people as well as their king. Gwen firmly disagreed, telling him that it was possible and he would prove it when he became king. She told him that he had a kind heart, and that he shouldn't change it for anyone (Beauty and the Beast). When Gwen and Merlin found evidence that Aredian had framed Gaius for sorcery, Gwen tried to persuade Arthur to halt his execution. The prince initially refused, telling her that since his father had already passed sentence there was nothing he could do, but Gwen angrily responded that he could do the right thing. That he could show some faith in his friends or stand back and watch an innocent man die, just as he'd done once before to her father. As Arthur stared at her in shock, she finished her rant by saying that she knew she was just a servant but she'd thought Arthur was a prince, and he should start behaving like one. Though clearly startled by the forcefulness of Gwen's tirade, Arthur was convinced by her words and stopped the execution (The Witchfinder).

Sweet Dreams
Uther is discusses a peace treaty with another king whos daughter "Lady Vivian" Is his pride and joy and if any man touched her it would ruin the peace treaty. A third party king who would be poor if the war ended asked his servant to enchant Lady Vivian and Arthur to fall in love.

When they do Arthur says to Merlin to send flowers to his love not specifying Lady Vivian Merlin places flowers and a note which says "All the barriers that keep us apart cant beat the power of true love - Arthur" Gwen is overjoyed and tells Merlin she is having the best day and that sometimes when you think everything is lost so mething happens to give you hope. Gwen leaves a note in Arthurs room unsigned that tells him he can have a second c hance and to meet her in her room. However she leaves it unsigned and Arthur  goes to lady Vivians room leaving Gwen waiting there until her candle goes out and Gwen is in despair. However Merlin tells her the only way to break the enchantment is to give him a kiss from his true love gwen kisses him and Arthur is returned to normal and saves Camelot from War. Proving Arthur is Guineveres true love and Guinevere is Arthurs ( Sweet Dreams ).

Waiting Game
In season 2 episode 13 Arthur saves Gwen’s life

In season 3 episode 3 Gwen farts in front of Arthur

In season 3 episode 5 Gwen cries in Arthur’s arms

In season 3 episode 10 "The Queen of Hearts" Morgana has a dream of Guinevere being crowned Queen of Camelot and in pain and jealousy decides to reveal their relationship to the King. She encourages Arthur and Gwen to spend time together. While Guinevere and Arthur are together, she encourages Uther to go for a horse ride and they "coincidentally" come across the two in the woods.

Later in the palace Uther laughs, and saying he too in his past understood the incitement of serving girls, but explained they may never see each other again. When Arthur continues to demand he is in love with Gwen, Morgana hides a magical pouch full of herbs under Arthur's pillow framing her of enchanting him. She is put to death and the two share one last desperate and beautiful kiss as she is taken away.

Before, however, she could be killed, with the help of Merlin Gwen escaped.

Later in the season...

In season 4 episode 9 "Lancelot du Lac" Arthur had asked Guinevere to marry him when Morgana found out she would do anything to keep a serving girl from her throne. Morgana uses necromancy to bring Lancelot back. then using magic brought back Gwen's feelings for him. Gwen and Lancelot are caught by Arthur who is furious and almost kills Lancelot but Gwen stops him, Gwen is thrown in jail. Crying, she throws off the enchanted bracelet from Morgana which caused her unnatural attraction to Lancelot. Afterwards to save Gwen from being put to death like his advisers suggest Arthur tells Gwen to leave camelot and never return. She asked where she would go but Arthur told her he didn't know. Arthur was so blinded by jealousy rage and heartbreak he sent her away. There was nothing else he could do. This was the lowest point for Gwen and Arthurs relationship.

Season 4 Episode 13 "The Sword in the Stone Part 2" Gwen and Arthur at long last marry. After seeing Tristan's lover die in his arms he realizes he cannot lose Gwen again. Arthur comes to Gwen as she is cleaning a room and asks her to marry him, as he never stopped loving her. She responds, "yes" with "all her heart".