With the erection of Maesyfed into the shire of Radnor in 1536 Rhayader was named as assize-town for the newly formed county in conjunction with New Radnor; but in 1542, on account of a local riot, the town was deprived of this privilege in favour of Presteign.
Rhayader constituted one of the group of boroughs comprising the Radnor parliamentary district until the Redistribution Act of 1885.
A chancery and exchequer for the counties of Brecknock and Radnor were also established at Brecon Castle, and from 1542 till 1830 the great sessions, and since then the assizes, and at all times the quarter sessions for the county, have been held at Brecon.
By Radnor, E.
The farming is, however, chiefly pastoral, nearly one-third of the county is common or waste land, and its number of sheep (mainly of the Radnor Forest breed) far exceeds that of any other county in Wales.