1. The medieval borough of Caerphilly lay outside the south gate of the colossal late thirteenth century castle (NPRN 94497). In 1281 there were 116 burgages or house plots, eighty of which were burnt in the war of 1294-5. By 1306 there were 44 burgages and there were 95 in 1314 and 98 in 1347. There was a weekly market and an annual fair. The borough is thought to have declined with the castle from the later fourteenth century, only to revive in the seventeenth century.
Something of the borough's layout can be discerned on the 1st edition OS County series (Glamorgan. XXXVII.2 1881) which shows a large triangular market place, the Twyn. The fourteenth century Court House by the castle's south gate survives, much altered and extended, as a public house (NPRN 18426).

Source: Beresford 'New Towns of the Middle Ages' revised edition (1988), 553
CADW Guide to Caerphilly Castle revised edition (1997), 20

John Wiles 05.02.08

Caerphilly developed greatly in the nineteenth century after the Industrial Revolution transformed the surrounding valley and it established itself as the main town of the valley.

2. Caerphilly is a town, community, and unitary authority. Located at the southern end of the Rhymney Valley, the town is connected with the medieval castle of the same name.
L. Moore, RCAHMW, 3rd February 2012