Helig ap Glanawg
Helig ap Glanawg (Helig ap Glannog in modern Welsh) is a legendary North Welsh figure said to be a 6th‑century prince. The stories go back to at least the 13th century.
According to later tradition, the River Conwy once reached the sea near the Great Orme at Llandudno. To the west lay the cantref of Gwaelod, stretching all the way to Puffin Island off Anglesey. Helig is said to have lived here when the land was flooded, creating the Lavan Sands between the Great Orme’s Head and the Menai Strait.
The legend says the remains of Llys Helig, thought to be Helig’s palace, can be seen at exceptionally low tides. They are actually the remnants of a glacial moraine, located near the Conwy channel about a mile off the coast at Penmaenmawr.
The name Llys Helig first appears in the Halliwell Manuscript, published in 1859, but that manuscript is thought to date from the early 17th century, several centuries after Helig’s time.
After the disaster, Helig and his many sons are said to have become religious. Different sources give different lists of his sons.
Rachel Bromwich notes that Cantre’r Gwaelod, a sunken kingdom tale from Cardiganshire, has similarities with Llys Helig. She suggests the two stories influenced each other and may share a common origin, with the Halliwell Manuscript calling Helig the “Lord of Cantre’r Gwaelod.”
Antone Minard writes that these Welsh legends share details such as bells heard under the waves and ruins visible at the equinoctial tides, which helps explain why people believe the stories.
This page was last edited on 2 February 2026, at 10:40 (CET).