Witches are humans gifted with the power to affect change by supernatural or paranormal means, a practice known as "witchcraft". Witches are generally female, though there are a few male witches, referred to as "warlocks". Because of their unnatural abilities and supposed connections with dark forces, witches have historically been feared, persecuted, and hunted. Many escaped the Salem witch trials and sought refuge in New Orleans. Among the population of witches, there is always one witch per generation who possesses a class of seven powers considered to be advanced acts of magic. This witch is known as the "Supreme". As the witches settled in their new territory, a rivalry between them and the native Voodoo practitioners arose. The feud is still ongoing in present-day New Orleans. A group of witches are the focus of Coven, in which magic is a genetic heredity that connects a person to the elements and forces of nature in order to practice witchcraft.
It has been attested that the witches of Salem received their power from the Voodoo slave girl Tituba, though evidently, their abilities stem from a genetic affliction that is passed down through bloodlines.  During the Salem witch trials in 1692, witches faced persecution and decided to flee south in the midst of the hysteria. However, their ailing Supreme, Prudence Mather, was unable to make the journey and decided to take her own life in a ritual known as the Sacred Taking. This selfless act allowed a new Supreme to take power and lead the Coven to safety, where they eventually settled in New Orleans. The generations of witches to follow would become known as the "Salem descendants". 
In 1868, the reigning Supreme of the time, Marion Warton, purchased Miss Robichaux's Academy for Exceptional Young Ladies as a safe haven where witches could gather to learn.  In 1919, the witches of the Academy killed the Axeman, putting an end to his murderous reign of terror in New Orleans. In 1926, a witch was tried and burned at the stake.
The witches of the Coven found a new enemy in the form of a Voodoo tribe lead by Marie Laveau, the Voodoo Queen. This sparked an ongoing feud in 1961 that lasted for about ten years, motivated in part by racial tension between the two groups. The bloody conflict would come to an end in 1971, when Marie Laveau and Supreme Anna Leigh Leighton signed a truce that entailed neither side crossing into the other's territory. 
Shortly after the truce was declared, Anna Leigh was brutally murdered by Fiona Goode in her endeavor to become the next Supreme. The only witness to this event was Spalding, a butler serving the witches of Miss Robichaux's Academy. Due to his infatuation with Fiona, Spalding cut out his own tongue when he learned that it had been enchanted to speak the truth by Fiona's rival, Myrtle Snow. The Council on Witchcraft presumes Anna Leigh to have been killed by the Voodoo tribe instead. They identify Fiona as Anna Leigh's successor to the Supremacy, and has her perform the Seven Wonders. Fiona successfully does this and is declared the Supreme, though she ultimately uses her power to satisfy her own selfish needs, instead of the betterment of the Coven.  In 1971, the witch Mary Oneida Toups led an alternative coven at Popps' Fountain in the French Quarter. 
In 2007, witch hunter Henry Renard allied himself with Marie Laveau in a joint effort to eliminate all the Salem descendants. He married Fiona's daughter, Cordelia, under the alias of "Hank Foxx" and used her research to secretly hunt witches.  By 2013, due to many families willingly deciding not to reproduce, the Academy's population dwindled from as many as sixty young witches to a total of four: Nan, Queenie, Madison Montgomery, and Zoe Benson. 
With her reign as Supreme coming to an end, Fiona returned to New Orleans upon learning that a witch by the name of Misty Day was burnt at the stake.  Freeing the immortal Delphine LaLaurie from her grave, Fiona sought to gain immortality herself by bargaining with Marie Laveau, who has been alive for centuries.  Unsuccessful, Fiona resorts to murdering her successor to the Supremacy, who she believed to be Madison after learning of the girl's magical talents.  When the Council arrives to investigate Madison's disappearance, Fiona learns from Cordelia that Madison was not the next Supreme due to a heart condition. That Halloween night, Cordelia is blinded by an acid attack orchestrated by the witch hunter corporation, Delphi Trust. 
In retaliation for the Minotaur's dismemberment at Fiona's hands, Marie Laveau declared war against the Coven and raises an army of the undead to siege Miss Robichaux's Academy. With Fiona tending to an injured Cordelia, the young witches are left to defend themselves from Marie Laveau's onslaught. Using a chainsaw and raw magical power, Zoe takes out the zombie army by herself. 
In light of recent attacks against the Coven, the Council demands Fiona's immediate abdication as Supreme. However, with Queenie's help, she frames Myrtle for Cordelia's assault and has her burnt at the stake. Misty Day, having resurrected herself, stumbles upon Myrtle's charred corpse and uses her power of resurgence to bring the former Council member back to life. 
Zoe, Madison, Misty, and Queenie performed the tests of the Seven Wonders. Misty died during the Trial of Descensum and Zoe died during the Trial of Transmutation. Myrtle convinced Cordelia to perform the Trials of the Seven Wonders as well. Cordelia performed Vitalum Vitalis and resurrected Zoe, ascending to the Supremacy. Cordelia exposed the existence of witches to the world and tried to get more witches to attend the academy. Many more witches attended the Academy and Cordelia stated that they should find more houses to house them all.
The Supreme Witch
The Witches' Council
The governing body of the witches and warlocks, depicted as very old-fashioned elders, as displayed by the fact that they still use typewriters in the modern times. They are responsible for policing witch crimes, the concealment of witchcraft to the uninitiated, and for the welcoming of potential students to Miss Robichaux's Academy. The council only visits the coven on very important cases, such as the death of another witch.
A number of magical powers and abilities have been showcased in Coven.
Some abilities are inherent or reflexive to certain witches, that is they do not need to focus or concentrate. It's not rare for a witch to manifest more than three powers, though a Supreme is required to have at least seven (the Seven Wonders), though not necessarily all possible powers. It is said that the reason that a Supreme is so powerful is that she is the physical embodiment of many and or all powers.
- Witches are shown to be able to use their powers collectively.
- Certain abilities can also be triggered by certain events and substances.
- Voodoo and witchcraft practitioners share certain powers.
- The way the Supreme is chosen is similar to how Slayers in the TV show Buffy the Vampire Slayer would be "activated", requiring a previous Slayer to die in order for a random person to potentially be the next generation's Slayers. Both Slayers and the Supreme are generally female and both shows have witches and supernatural creatures.
- The earliest known American coven (in the series) are descendants of Salem witches, but mythology relating to witches existed beforehand, indicating other types of witches may exist; Scáthach and Marie Laveau are two examples of this. Also, the Delphi Trust has been hunting witches since before the trials of Salem.
- Scáthach is the first known human to become a witch in the AHS universe, opposed to being genetically born one. This may imply that normal humans can become witches through the sacrificial worship of the old gods.
- The former Supreme Mimi DeLongpre shares the same surname as supposed distant cousins of Constance Langdon and parents of Michael Langdon in her cover story in the final episode of Murder House. "He was the child of distant cousins on my mother's side. The DeLongpres of Virginia, Eveline and Steve."
- ↑ Martin, Denise. Ryan Murphy Reveals More American Horror Story: Coven Plot Details.
- ↑ 2.0 2.1 Episode: Boy Parts
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Episode: Bitchcraft
- ↑ Episode: The Sacred Taking
- ↑ 5.0 5.1 5.2 Episode: Fearful Pranks Ensue
- ↑ Episode: The Dead
- ↑ Episode: The Replacements
- ↑ Episode: Head
- ↑ 9.0 9.1 Episode: Burn, Witch. Burn!