The earliest reference to Glanhirin appears in a document dating to 1696 (Banks, 1880, 49) although there is no indication as to how long it had existed before that date. is shown on the 1833 1 inch to 1 mile map as a building with a long straight rectangular parcel of land to the east and a field beyond. On the Llansanffraid Cwmteuddwr parish tithe map of 1841 it is shown as two fields, Bryn Bychan and Bryn Llwyd with the building external to Bryn Llwyd. At that time it was owned by Henry Pulham Clinton, Duke of Newcastle, and, according to the 1841 census, tenanted by Rees and Margaret Lewis. By the time of the 1st edition 1:10560 Ordnance Survey map of 1891, the two fields have been subsumed into a larger, more rectilinear field system, closer to the field system in existence today. Since the late 19th century the farm has been part of the estate formed by the Birmingham Corporation when the Elan Valley reservoirs were created. Erwyd Howells writes about Glanhirin in his 2005 book ?Good Men and True? giving some stories about its former tenants. In 2009 Glanhirin was still occupied and farmed by tenants.

In the 19th century and early 20th century access to the post medieval farmstead was by a trackway, NPRN 503528. The modern access track, NPRN 502704, was built by the Elan estate in the later 20th century. The field system NPRN 503509 developed during the mid 19th century to resemble the field system in existence today. A group of possible pillow mounds, NPRN 24595, now badly damaged, lie within the modern field system. Two other previously recorded groups of pillow mounds, NPRNs 24596 and 304802, were discounted as natural features during Upland Survey in 2009. The farmyard now consists of the farmhouse, NPRN 503532, and adjoining stone-built building, NPRN 503600, as well as more recent agricultural buildings, NPRN 503597, 503598 and 503599.

Source: Banks, R.W., 1880. `The Grange of Cwmtoyddwr?, Archaeologia Cambrensis, 4th series XI, p.49.
Source: Erwyd Howells (2005), Good Men and True, p32.

J.J. Hall, Trysor, 31 January 2010