Lancelot

Lancelot is an episodic character on Once Upon a Time. He was at one point a knight of the Round Table, though due to unspecified reasons he was banished from his country, as well as his true love.

Before the Curse
Lancelot is hired to be King George's fearsome new general who will aid him in hunting down Prince Charming. In battle, he comes across Snow White and introduces himself as Lancelot, she recognizes this name as being a part of the roundtable, but he assures her that he isn't anymore, before advancing on her. Later, he takes a bag off of Snow's head and presents her to King George, the King asks Lancelot to get Snow and drink and he obliges, however, it is soon revealed that the drink was laced with a curse that makes the drinker infertile, meaning Snow can no longer have children, Lancelot appears to have been none the wiser. Snow is let go and sees a horse containing Lancelot riding in the forest, she picks up a pole and whacks him off of his horse with it, before threatening him for what he did to her. He reminds her that it was the King that did it to her before warning her that soldiers are on their way to attack Charming where his mother is hiding. They arrive just as Ruth has been shot by a stray arrow to the chest, it is Lancelot who realizes that the arrow is poisoned and that there is therefore an antidote, and so Charming suggests that they use the waters of Lake Nostos to heal her. On the way there, Charming questions how Lancelot came to be a disgraced knight, he tells him that it was for a woman. When they arrive, they are shocked to see that the lake is completely empty, but Lancelot, who was raised by a lake, tells him that there shall be water somewhere if they look, and, sure enough, he finds a small morsel, enough for one sip. It is given to Ruth but does not work and her final wish is to see Snow and Charming married, and so Lancelot marries them before Ruth's eyes. During the ceremony, they are made to drink from a wedding chalice and it is revealed that the morsel from the lake was in that chalice, making Snow fertile once more. After Ruth's death, Snow realizes this, and, having used Ruth's superstitious necklace to determine the gender of her baby, Lancelot asks what it will be. She replies that it's going to be a girl.

Season 2
It is revealed that there is a section of fairytale land that was unaffected by the curse, it is now a dangerous place where people have taken refuge in a safe haven, and Lancelot is their leader. When Snow and Emma end up there accidentally, they are taken prisoner by Mulan and Aurora. They encounter Cora in "the pit" and Snow warns Emma how evil she is, they are soon set free when Lancelot demands it. Aurora is angry when Snow and Lancelot embrace, blaming the newcomers for the death of Prince Phillip as they came through the same portal that brought the Wraith to their land. Mulan warns Aurora not to do anything about this, however, Aurora is revealed to have a dagger concealed for Emma and Snow. Snow requests that she and Emma go to her old castle so that they may travel to their old land through a wardrobe that sent Emma to Maine twenty-eight years previously. Lancelot is unsure of this, telling Snow that the ogres have returned, Snow persists and Lancelot allows it on the condition that the take Mulan, his finest warrior, with them. They agree. On their voyage, Aurora makes an attempt on Snow's life which is overruled, they finally make it to the castle after an ogre attack (one that Snow slays) and find the wardrobe. They are met there by Lancelot who seems to take interest in the wardrobe, and Snow wonders why. He says he just wants her to get back to her husband, and for Emma to get back to her son, Henry. At this, Snow pulls a sword on Lancelot, telling Emma that he is not who he says he is as there is only one person that she told Henry's name. Then, in a swirl of purple mist, Lancelot reveals himself to be Cora in disguise, the evil witch tells them that she killed Lancelot long ago and has been posing as him ever since. She tries to attack the two princesses so that she can make it through the wardrobe, however, Emma burns it down.

Gallery
Gallery of photographic stills released to promote the character.