The
cantref of
Buellt, which lends its name to the modern town, was centered around Builth, and remained unusually independent of larger powers during the
Early Middle Ages. The first major development recorded at the location of modern Builth was an 11th-century
Norman motte-and-bailey castle, built by the
marcher lord Philip de Braose on the banks of the Wye, where it overlooked an important ford across the river. Due to its highly strategic position, the castle regularly traded hands between the native Welsh princes and the marcher lords vying for control of the
Welsh Marches. Later on, during his
conquest of Wales in the late 13th century, the English king
Edward I ordered the construction of the much larger, stone-built
Builth Castle on the site of the older fort. In 1278, he also granted the town of Builth, which had sprung up around the fortification, the right to hold a market. On 27 December 1690, a devastating fire tore through Builth, which at the time had a population of roughly 400. A significant part of the town was destroyed, with damages of £10,780 recorded, equivalent to millions today. Although donations towards the rebuilding effort came from as far afield as Lincoln, very little made it to the ordinary inhabitants of the town, who were forced to take apart the masonry of the castle to rebuild the town. During the
Victorian era, Builth began to gain a name for itself as a
spa town, with the springs at Glanne Wells and Park Wells attracting significant tourism to the area. This success was buoyed by the opening of a
railway station in 1860, which dramatically increased the towns popularity. The town's population grew substantially in this time period, from 677 in 1801 to 1,455 in 1881, and the town itself saw significant urban development, such as a drainage and water system installed in 1868 and a major expansion of housing to fit the growing populace. As the tourism industry declined, Builth turned towards agriculture, and the town acquired its first dedicated livestock market in 1910. This eventually led to the
Royal Welsh Agricultural Show settling on nearby
Llanelwedd, just across the river, as its permanent home in 1963. ==Governance==