What is a will-o’-the-wisp?
In the account selected here, it is a misleading fairy light associated with marshy ground. Wirt Sikes compares the Welsh Ellylldan to the English Will-o’-wisp. This profile follows his Welsh account, without treating the two names as proof of an identical tradition everywhere.
Source status and limits
The evidence is a nineteenth-century folklore collection, not a contemporary record of supernatural events. Sikes combines general statements with a literary account he explicitly condenses and attributes to Iolo the Bard, citing The Vale of Glamorgan (London, 1839) in footnote 15. That earlier work has not been independently used here.
His comparisons with other cultures are the collector’s interpretation. This profile does not transfer their appearances or powers to the Ellylldan, or adopt his proposed word derivations as established linguistics. Ellylldan is retained as the culturally specific name of the Welsh subject, rather than listed as an unrestricted English alias.
- record type
- creature
- tradition
- Welsh folklore as presented by Wirt Sikes, with an explicit comparison to the English Will-o’-wisp.
- source scope
- Wirt Sikes, British Goblins: Welsh Folk-lore, Fairy Mythology, Legends and Traditions, London: Sampson Low, Marston, Searle, & Rivington, 1880; Book I, Chapter II, section IV, pp. 18–19. This profile covers the Ellylldan account Sikes compares to the English Will-o’-wisp, rather than a composite of wandering-light traditions.
- aliases
- ["Will-o’-wisp"]
- period
- Documented in the selected 1880 folklore collection; not a date of origin.
The source account
Sikes describes the Ellylldan as leading a late traveller into marshy ground. In the condensed literary episode, a narrator follows its light from a hillside into a wet valley. When he stops, the light waits and dwindles; when he resumes walking, it brightens and moves ahead. It finally joins a circling company of similar lights, whose dance sends him to sleep.
These events belong to this particular narrated episode. They do not establish a universal set of abilities for every being called a will-o’-the-wisp.
Appearance and behaviour
The Welsh passage supports a moving, glowing light that changes its apparent brightness and draws a follower onward. It does not supply a definite bodily shape, dimensions, wings or facial features for the Ellylldan. The detailed creature descriptions in Sikes’s neighbouring cross-cultural comparisons should not be read as its anatomy.
Source realm
The setting is earthly wetland: marshes, pools and a valley encountered at night. The selected account does not name a separate supernatural kingdom or establish a fixed geographical range.
For regional context, see British Folklore: Regional Creatures and Legends.