The origin of the King Arthur tales technically goes back to Wales, but the story has been retold many different times over the centuries. It wasn’t just popular in the British Isles—it also became a favorite among people in France and Germany.

In some of the earliest King Arthur stories, he isn’t a king at all but a warrior who fights monsters and other evil beings.

It is very likely that King Arthur is based on a real-life Romano-British general who resisted the invasion of the Saxons.

A major reboot of the King Arthur stories came in the 12th century from a French poet named Chrétien de Troyes. He also introduced the character of Lancelot. Later French tellings would coin the name Camelot.

The importance of the Round Table was that all of Arthur’s knights were considered equal. He was said to have had a hundred different knights, though only a handful were actually notable.

The character of Merlin may have been based on a Welsh prophet named Myrddin Wyllt, who went mad from war. In some stories, Merlin is said to age backwards—somewhat like Benjamin Button.

In the most traditional versions of the tale, Arthur was raised by Sir Ector and did not know he was actually a royal prince destined to be king until he pulled the sword from the stone.

Excalibur is traditionally not the same sword as the one in the stone. Arthur famously receives Excalibur from the Lady of the Lake. The name “Excalibur” is believed to mean “cut steel.”

Traditionally, Arthur has two half-sisters: Morgause and Morgan le Fay. They are usually portrayed as evil, though not always. One of them is typically the mother of Arthur’s son, Mordred.

The character of Queen Guinevere has changed significantly over time. She was once portrayed as a loyal queen, sometimes a political pawn, but more recently is traditionally shown as the woman who betrays Arthur for the knight Lancelot.

The most noble in purity of Arthur’s knights was Sir Galahad, the son of Lancelot, ironically. Traditionally, he is the one who finds the Holy Grail.

The Lady of the Lake goes by different names in various stories, including Nimue, Vivien, and Ninianne.

The character of Mordred is traditionally Arthur’s inbred son from his sister. However, in some versions, he is not evil and is even portrayed as Arthur’s legitimate heir.

Most of the Arthurian stories we know today come from Sir Thomas Malory, who wrote Le Morte d’Arthur in the 15th century, meaning “The Death of Arthur.”

The Holy Grail wasn’t always a Christian idea; in earlier versions of the story, it replaced a Celtic cauldron of rebirth.

King Arthur is often called “The Once and Future King,” as it was always said that he would return one day when Britain needed him the most.

Traditionally, Arthur’s final resting place is the legendary island of Avalon.

Real-life British monarchs have claimed that King Arthur was real. When Henry VII became king of England, he named his son Arthur to invoke the King Arthur legend and strengthen his claim to the throne. Two princes named Arthur nearly became kings of England but died tragically. Arthur Tudor died of an illness, and Arthur of Brittany was murdered by his uncle, King John, who wanted the throne for himself.