Llanfyllin was named after the seventh century St. Melyn, the first baptist in Britain (‘Mewn Llwyn’ – ‘Saint in the Pool’), to whom the local church is dedicated. The town was incorporated in 1293, when it received its charter granting a weekly market and annual fair from Llewelyn ap Grufydd ab Gwenwynwyn; Llewelyn the Last. Llanfyllin, together with Welshpool, is one of only two Welsh towns to have received its charter from a native ruler. It was later granted privileges and immunities by Edward I, and Charles II confirmed the foundation charter.
There are a number of malt kilns in the vicinity of Llanfyllin, malt having been its principle trade for much of its history; there were also tanneries, corn mills and a woollen mill. A quarry was established to the north west of the town. The weekly market was held beneath the Town Hall, which also served as a National School and was where all public business took place. The former workhouse was recently restored and now serves as a focal point of the community.
Source: Lewis, S. A Topographical Dictionary of Wales, 1833