Name of Place: Oldcastle; County: Monmouth; Number of Miles from: Abergavenny – 7; Crickhowel – 9; Hay – 15; Dist. Lond. – 143; Population: 73.
Oldcastle. This parish is famous for having giving birth to that eminent ecclesiastical reformer, Sir John Oldcastle, Lord Cobham, who was styled by Horace Walpole, “the first author, as well as the first martyr, among our nobility.”
Source: England and Wales Delineated by Thomas Dugdale assisted by William Burnett; published by Tallis & Co., Green Arbour Court, Old Bailey, 1835.