Sidhe

"The Sidhe are a vicious people. You must be careful."

- Gaius to Merlin

The Sidhe are a race of immortal blue fairies that inhabit the land of Avalon. They are powerful creatures of magic and masters of enchantment.

History
When Princess Elena of Gawant was born, a Sidhe Elder cast an enchantment that turned her into a changeling. He left his pixie servant Grunhilda to watch over Elena and keep the Sidhe within her dormant until the time came for it to possess her entirely (The Changeling).

After Aulfric killed another Sidhe, he and his daughter Sophia were exiled from Avalon to live mortal lives. To save Sophia from sharing his fate fate, Aulfric directed her to enchant Arthur with a love spell and they offered him to the Sidhe Elders as a sacrifice. However, Merlin saved Arthur by killing Aulfric and Sophia with Sophia's staff (The Gates of Avalon).

When Elena was twenty years old, her father Lord Godwyn and Uther Pendragon organised a marriage alliance between her and Arthur. Because Elena was a changeling, their union would have given the Sidhe control over the throne of Camelot after the fairy inside of her emerged and possessed her entirely. Fortunately, Merlin and Gaius concocted a potion to force the Sidhe out of her. The Sidhe Elder tried to stop them, but Merlin destroyed him with a the staff that perviously belonged to Sophia. Later, after Elena drank the potion, Merlin used the staff to destroy the Sidhe that left her body (The Changeling).

When Arthur was mortally wounded in the Battle of Camlann, Gaius determined that only magic as old as the dragons could save him and advised Merlin to take Arthur to the Lake of Avalon. They planned to ask the Sidhe to use their magic to heal him, but Arthur died before they reached their destination (The Diamond of the Day).

Abilities
The Sidhe are powerful creatures of magic and masters of enchantment. They are able to cast powerful spells and often use staffs to focus their magic. For example, both Aulfric and the Sidhe Elder used their staffs to direct bolts of energy at Merlin (The Gates of Avalon, The Changeling).

The Sidhe practice their own branch of magic known as Sidhe magic, which, according to Gaius, is as old and powerful as the dragons themsleves. It can be used to cast powerful love and healing spells, and to create changelings by implanting a Sidhe inside a human. A fairy can live within its host for over twenty years, and can emerge and possess them at any time (The Gates of Avalon, The Changeling, The Diamond of the Day).

In addition to magic, Sidhe also have the ability to fly and to take the form of a small sphere of light. Though they have a lifespan of over a thousand years, they are not completely immortal, as they can be killed by powerful forms of magic and can be cursed to live mortal lives (The Gates of Avalon, The Changeling).

Appearances

 * Series 1
 * The Gates of Avalon


 * Series 3
 * The Changeling


 * Series 5
 * The Diamond of the Day: Part Two

Trivia

 * While in human form, a Sidhe's eyes turn red when using magic (The Gates of Avalon).
 * According to Gaius, the Sidhe have a lifespan of more than a thousand years (The Changeling).
 * The Sidhe are ruled by a council of Elders, who are often served by pixies (The Gates of Avalon, The Changeling).

Etymology

 * Sidhe (pronounced "shee") is a word of Gaelic origin and means "people of the fairy hills".

Mythology
The Aos Sí (also called Síth) are a supernatural race comparable to fairies or elves in Gaelic folklore. They are said to descend from either fallen angels or Túatha De Danann, and have been described as both stunningly beautiful and terrible and hideous.

Aos Sí live underground in fairy forts, across the western sea, or in an invisible Otherworld that coexists with the world of humans. They are fierce guardians of their homes and will often punish invaders by kidnapping them or replacing their children with changelings. As such, great care is taken to avoid angering or insulting them, though they can be appeased with offerings.