The melody dates back to at least the 18th century, with the earliest printed version appearing in Edward Jones’s “Musical and Poetical Relicks of the Welsh Bards” in 1784. The original Welsh lyrics were written by John Ceiriog Hughes, a celebrated Welsh poet, though various English translations have emerged over the centuries.

The song gained international popularity during the Victorian era when it was arranged for formal choral performances. Its haunting melody and lullaby-like quality have made it a favorite across the British Isles and beyond, leading to its adoption into many folk traditions including Irish collections. Though not authentically Irish in origin, the song has been performed by numerous Irish musicians and has become part of the broader Celtic musical heritage.