LLANTHEW, or LLANDDEW, a parish in the district and county of Brecon; on the river Honddu, 1½ mile NE of Brecon r. station. Post town, Brecon. Acres, 2,695. Real property, £1,352. Pop., 292. Houses, 68. The manor belongs to the Bishop of St. David's. An ancient palace of the bishops stood here; was visited, in 1188, by Archbishop Baldwin and Giraldus; was ordered, by a statute of 1342, to be retained as an episcopal residence; and is now represented by some ruins, including a door-way built by Bishop Gower. The living is a vicarage in the diocese of St. David's. Value, £89. Patron, the Archdeacon of Brecon. The church is dedicated to St. David; is early English and cruciform; and has been greatly mutilated, yet retains traces of pristine beauty.

(John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72))