How the name originated is unknown, but in 1900 a local journalist wrote a creative Victorian-era history of the location, suggesting that it was the site of a battle between the native Celts and the Romans.

Glyncoch lies halfway between known Roman forts built at Pen-y-coedcae and above Llanwynno, and so could have been located on a pathway between the two.

During the Middle Ages, pilgrims travelled up the valley to the shrine of the Virgin Mary at Penrhys, with many taking refreshment or staying at an inn, believed by historians to be located close to the current Berwerdy Cottages.

By the 19th century, during the industrial development of the South Wales valleys, the land was owned by the Griffiths family.

On the death of their son, the Cardiff-based doctor Richard Griffiths, he was carried in procession from Pontypridd, through Glyncoch and Ynysybwl, to the church at Llanwynno where he is buried.