Nightbringer | The Arthurian Online Encyclopedia

Gweir White Shaft

One of four brothers, all named Gweir, who were Arthur’s maternal uncles,

the uncles of Arthur, the brothers of his mother

and sons of Llwch Windy Hand (Llwch Lleminawc) “from beyond the surging/Tyrrhene sea”.

This identifies Arthur’s mother as Eigyr, daughter of Anlawdd Wledig.

See also
Gweir | The Legend of King Arthur
Gweir Falsevalor | The Legend of King Arthur

Culhwch and Olwen | Late 11th century