Donn, the name means the dark or brown one, is the lord of the dead in Irish tradition, a shadowy ancestor-god who stands somewhat apart from the bright company of the Tuatha De Danann. He dwells on a small rocky island off the south-west coast of Ireland called Tech Duinn, the House of Donn, and to this island, the tradition holds, the dead of Ireland gather on their way to the otherworld, Donn's house is the assembly-place of the departed, the first gathering-point of the souls of the dead. In one strand of the mythological history Donn is counted among the Milesians, the ancestors of the Gaels, and is said to have drowned off that same south-western coast during their invasion of Ireland, so that the god of the dead is at once an ancestor of the living people; his dying words in some tellings invite his descendants to come to him at his house after death.
Donn is a comparatively obscure figure, glimpsed rather than fully drawn in the surviving sources, and much about him is uncertain. But he preserves a genuinely archaic idea: a god of the dead who is also a first ancestor, and a particular place on the edge of the sea, a real island still bearing his name, imagined as the gathering-house to which all the dead of the land make their way. He shows the Irish tradition's tendency to locate the otherworld not in some abstract elsewhere but at specific points in the actual landscape, at the western margins where the land gives way to the ocean.