Blockula (Blåkulla in modern Swedish, translated to "Blue Hill") was a legendary island where the Devil held his Earthly court during a witches' Sabbath. It was described as containing a massive meadow with no visible end, and a large house where the Devil would stay.
Referencing Blockula nights, witches described the Devil as appearing, "in a gray Coat, and red and blue Stockings: He had a red Beard, a high-crown’d Hat, with Linnen of divers Colours, wrapt about it, and long Garters upon his Stockings."
Blockula plays a major part in the witch-hunts described in Joseph Glanvill's 1682 work Sadducismus Triumphatus, which detailed the Mora witch trials in an Appendix entitled: "True Account of What Happen’d in the Kingdom of Sweden In the Years 1669, 1670, and upwards: In Relation to some Persons that were accused for Witches; and Tryed and Executed By the King’s Command."
Blockula is originally the same place as the island Blå Jungfrun, which was in old days called Blåkulla, and since medieval days rumored to be a place where the witches gathered. The perhaps first time Blockula was mentioned in a witch trial by an alleged witch was in 1597, but in reality, it was not until the Swedish witch mania of 1668-1676 that the place had any real importance in the persecution of witches.[citation needed]