The Sluagh, or Sluagh na marbh (“host of the dead”), are the hosts of the unforgiven dead in Irish and Scottish folklore. The British folklorist Lewis Spence wrote that in the Western Isles of Scotland the Sluagh, or fairy host, was regarded as the souls of the dead flying through the air, and that the Hallowe’en feast of the dead was likewise the festival of the fairies.
Usually taking a crescent form like a flight of birds, they were said to approach from any direction, pick a person up, and carry them far through the air from one island to another. Though they would sometimes rescue people from dangerous clefts in the rock, they were generally portrayed as dangerous to mortals.
The name comes from Old Irish slúag, “host, army, crowd,” from a Proto-Celtic root whose original meaning may have been “those serving the chief.” As a procession of the dead that lifts the living away, it is often set beside the Wild Hunt and the Galician Santa Compaña.