In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Ystradmeurig like this:
YSPYTTY-YSTRAD-MEIRIC, a parish in Tregaron district, Cardigan; 5½ miles NNE of Tregaron r. station. Post town, Tregaron, under Carmarthen. Acres, 945. Real property, £13,469; of which £12,260 are in mines. Pop., 160. Houses, 30. A cell to Strata-Florida abbey was here, and was used as a hospitium. A castle also was built here by Gilbert de Clare; was frequently taken and retaken in the Welsh wars; and was demolished, in 1207, by Mallgwyn. A. hill-fort and a cairn still exist. The living is a p. curacy, annexed to Yspytty-Ystwith. There is an endowed school with £87 a year.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Ystradmeurig has changed, please see our redistricted information for the modern district of Ceredigion. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Ystradmeurig and units named after it.
GB Historical GIS / University of Portsmouth, History of Ystradmeurig, in Ceredigion and Cardiganshire | Map and description, A Vision of Britain through Time.
Date accessed: 11th March 2014
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Ystradmeurig".