Historically part of the parish of Radyr, the modern settlement of Morganstown has its origins in the late eighteenth century.

The Radyr tithe map of the early 1840s shows the existence of several cottages on the west side of what is now Tŷ Nant Road, on land belonging to Morgan William(s).

Most of the families relied for their living on one of the industries of the lower Taff Valley, with many of the men being employed as colliers, iron miners, puddlers, firemen, and coke burners.

Also buried there are two victims of the 1875 disaster at the Lan colliery (Gwaelod-y-garth), including the 13 year-old Moses Llewelyn, who worked as a door-boy at the mine.

The earlier name of Tynyberllan (literally ‘orchard homestead’ and formerly used in both English and Welsh) has not been used to refer to Morganstown since the middle of nineteenth century.

The use of Treforgan appears to have been particularly associated with Bethel chapel in Welsh-language sources, built as it was on land given by Morgan William(s) and later the location of his grave.

It may be significant that Evan Jones, who was appointed curate of Radyr in 1853, called the settlement 'Pentrepoeth' in memoirs published in 1897 (he was of course an Anglican rather than a Methodist).

The name Pentre-poeth is known from several areas where Welsh is or was commonly spoken, including Bassaleg, Gelligaer, Llangyfelach, Machen, Oswestry, Pwllheli, and Tywyn.

[10] The example of Pentre-popeth from Pwllheli has been translated as 'a burnt area near the boundary of a township' (Morganstown is at some distance from the parish church of Radyr, now in Danescourt).

Edward Matthews (1813–1892), then living at Canton near Cardiff, in the Calvinistic Methodist magazine Y Cylchgrawn (1874), suggests that some of the residents were annoyed at the continuing use of Pentre-poeth and considered Treforgan to be a more suitable name.