- “Whoso pulleth out this sword of this stone and anvil is rightwise King born of England.”
- ―Inscription on the Sword
According to the opening narration, the sword first appeared after the death of King Uther Pendragon, the King of England. The king had died, but no one knew who the rightful heir to the throne was. War threatened to break out, and could only be stopped by a miracle. One day, in the town of London, a light shone from the sky, and in a churchyard there, a sword appeared. The sword was lodged in an anvil placed on a stone. An inscription below the hilt, written in gold letters stated the sword's purpose. Due to the setup, the sword became known as the Sword in the Stone. The narration continues to tell that many knights and other nobles attempted to remove the sword, but all who tried failed. The miracle was considered a failure, and eventually, the sword was forgotten, leaving England in the Dark Ages and without a king.
It also seems to have some form of magical recognition of whoever tries to pull it, as even after it was returned to the stone after being pulled, it could not be pulled out again except by the one it deemed worthy.
Many years later, Wart is in London with Sir Ector and Sir Kay. He has been chosen to be squire to Kay during a tournament that will decide who is to be king. Unfortunately, Wart forgets Kay's sword, and so rushes off to find another, with the help of Archimedes, Merlin's owl. Wart spots a sword, lodged in a stone, in a churchyard. Archimedes warns Wart not to mess with the sword, but Wart knows that Kay must have a sword, and effortlessly removes it, inadvertently fulfilling the sword's prophecy.Wart returns to Kay with the sword, but Kay is able to tell that it is not his. Sir Ector notices the inscription, and another knight, Sir Bart, announces that the sword in the stone has been successfully pulled. Sir Ector asks where Wart got the sword, and Wart recounts the tale. No one believes him, and so everyone heads to the churchyard. Ector places the sword back in the stone, and tells Wart to pull it. Before he can do so, Kay pushes Wart out of the way and tries to pull it himself, stating that anyone else can pull it after it was already pulled out. Other knights join Kay, but they all fail. Sir Bart and Sir Pellinore both agree that Wart should try. Wart does so, and is once again able to pull the sword effortlessly, showing that he is the rightful king of England. After Wart is crowned King Arthur, he is shown with the sword, which has been placed in a scabbard.
To boost Snow White's confidence about facing the Evil Queen, Prince Charming constructed a fake version of Excalibur and planted it in a stone. When Snow pulled it out, believing it to be the real one, she was able to overcome the Queen based on this belief. Rumplestiltskin later destroyed the sword to prove that it was fake, and Snow is mad at Charming for lying to her. They make up, however, when she realizes that he did it to help her believe in something he already knew.
The real sword was shown in the fifth season. It was originally the Holy Grail that gave Merlin and Nimue their powers. Later, Merlin used the Flame of Prometheus to reforge it into the sword Excalibur when the threat of Vortigan arose and due to Merlin's desire to live a normal, mortal life with Nimue.
In a flashback, it was revealed that Excalibur was once attempted to be pulled out of the stone by Sir Kay. He fails and is disintegrated. When King Arthur pulls Excalibur from the stone, he finds that the tip of Excalibur is missing. It turns out that the tip had been made into the Dark One's Dagger. King Arthur seeks to unite both items in order to make Excalibur complete; this task has driven Arthur insane, and drove those he cared for away from him.
Using the Promethean Spark obtained from Nimue's heart, Emma unites Excalibur and the Dark One's Dagger into one weapon. The manifestations of Rumplestiltskin, Nimue, and the other previous Dark Ones tempt Emma into using Excalibur. It is later revealed that Excalibur now bears the names "Emma Swan" and "Killian Jones", who are the current Dark Ones now. Emma sought to take the darkness out of both of them and put it in Zelena, who she forced to give birth sooner to avoid killing the baby so that no one would have any qualms with killing her to put an end to the Darkness' threat. Killian's name is on it because she removed Merlin's tethering that Zelena put on it, and tethered Killian to the sword instead, in order keep Killian from dying from a cut that Excalibur inflicted on his neck, which Emma previously healed but was beginning to become undone.
Captain Hook later steals Excalibur from Emma to prevent her from using it as a way to prevent those that she knows from taken the temporarily-revived Dark Ones before her and Mr. Gold from taking their places on Earth. When Captain Hook fights Nimue's influence, he uses Excalibur to suck the previous Dark Ones into it. Upon Captain Hook's advice in order to keep the Darkness from escaping, Emma impales Captain Hook with Excalibur, which seemingly defeats the Darkness and kills all of the past Dark Ones, destroying Excalibur in the process.
However, a part of Excalibur may have survived, as Mr. Gold had used a magic potion to turn Excalibur into a conduit, transferring the Darkness back into himself to become the most powerful Dark One ever. In the process, a new Dagger of the Dark One was generated, which may contain some of the original Excalibur's powers.
The sword is featured in the sequel novel, Return to the Isle of the Lost: A Descendants Novel. Ben borrows it from Artie, Arthur's son, and uses it against Madam Mim.
A replica of the Sword in the Stone appears in the Fantasyland area of every Disney Park. It appears to be similar to the film depiction, but the stone has a plaque that gives an explanation of the sword. The Sword replicas were often accompanied by a short show where Merlin would take children from the audience to try their luck at pulling the sword for an opportunity to be crowned ruler of Fantasyland.
The Sword appears in Disneyland and Disney's Hollywood Studios versions of Fantasmic! where it is drawn by Mickey Mouse, dressed as the Brave Little Tailor, and used against Dragon Maleficent in lieu of the Sword of Truth Instead of stabbing the Dragon in the heart, Mickey instead uses it to shoot a magic blast at the beast, and in doing so he destroys the other villains in the process.