Banshee

The bean sidhe ("woman of the fairy mounds") is a herald rather than an agent: her keening (caoineadh) at night foretells a death in a family, but she does not cause it. In the older Irish material she attaches to particular lineages, traditionally the great families whose surnames carry O or Mac, and her wailing is understood as the supernatural counterpart of the human keening women who lamented at wakes.

Related figures appear across the Gaelic world: the Scottish bean nighe ("washer-woman"), seen washing the bloodstained clothes of the one about to die, is a close cousin. In some accounts the banshee is a beautiful young woman, in others a hideous hag, and she may comb her hair, a detail tied to a folk taboo against picking up a comb found lying out of doors. The banshee is one of the most durable figures of Irish folklore and has passed, much diluted, into English as a byword for a piercing scream ("wailing like a banshee"), a usage that keeps the cry and drops the mourning that gave it meaning.

The bean si is not attached to everyone. Irish tradition gives her to particular families, the old Gaelic lineages whose surnames carry O or Mac, and part of the point of the belief was that being warned in this way was a mark of descent. Later tellings drop that restriction and make her a general omen, which removes the social claim that the tradition was making.

She is best understood beside the keening woman. Caoineadh, the formal lament, was performed at Irish wakes by women, sometimes hired, working to a recognisable structure of praise, reproach and cry. The church objected to it repeatedly, the practice thinned through the nineteenth century under clerical pressure and then under the disruption of the Famine and emigration, and recordings of it were made only at the very end. A supernatural woman who wails for a death and a professional woman who wailed for a death stand very close together, and the tradition itself sometimes says so.

The washing figure at the ford, seen scrubbing bloodied clothes belonging to someone about to die, is a related but distinct being in the Irish and Scottish material. The two are frequently merged in retellings. Keeping them apart is worth the effort, since one announces a death and the other shows you whose.