There is a long history of human activity in the Machynlleth area. In the late-1990s, radiocarbon dating showed that copper mining was taking place in the Early Bronze Age (c. 2,750 years ago), within a mile of the town centre.
There are legends of a once fertile plain, the Cantre’r Gwaelod, now lost beneath the waves of Cardigan Bay.
The Romans settled in the area; they built a small Roman fort at Pennal (Cefn Caer) four miles west of Machynlleth, and are reputed to have had two look-out posts above the town at Bryn-y-gog and Wylfa. One of the earliest written references to Machynlleth is the Royal charter granted in 1291 by Edward I to Owen de la Pole, Lord of Powys. This gave him the right to hold “a market at Machynlleth every Wednesday for ever and two fairs every year”. The Wednesday market is still a busy and popular day in Machynlleth 700 years later.
The Royal House, which stands on the corner of the Garsiwn, is another of the mediaeval houses that can still be seen today. According to local tradition, Dafydd Gam, a Welsh ally of the English kings, was imprisoned here from 1404 to 1412 for attempting to assassinate Owain Glyndŵr. After his release by Glyndŵr, ransomed Gam fought alongside Henry V at the Battle of Agincourt and is named amongst the dead in Shakespeare’s Henry V. The name Royal House undoubtedly refers to the tradition that Charles I stayed at the house in 1643.
The weekly market and biannual fair thrived, and in 1613 drew complaints from other towns whose trading in cloth was being severely affected. A document dated 1632 shows that animals for sale came from all over Merionethshire, Montgomeryshire, Cardiganshire, Carmarthenshire and Denbighshire, and prospective buyers came from Flintshire, Radnorshire, Brecknockshire, Herefordshire and Shropshire, in addition to the above.
The Dyfi Bridge was first mentioned in 1533, by Geoffrey Hughes, “Citizen and Merchant taylour of London” who left £6 13/4 “towards making of a bridge at the toune of Mathanlleth”. By 1601 “Dyfi bridge in the Hundred of Mochunleth” was reported to be insufficient, and the current one was built in 1805 for £250. Fenton describes it in 1809 as “A noble erection of five large arches. The piers are narrow and over each cut-water is a pilaster, a common feature of the 18th century”.
Rowland Pugh was the Lord of Meirionedd, and lived at Mathafarn about two miles east of Machynlleth. Pugh supported the Royalist side in the English Civil War. On 2 November 1644, Sir Thomas Myddleton of Chirk Castle was marching on Machynlleth with a force of the Parliamentarian army, when he was ambushed by a force organised by Pugh. In retaliation for the attack, Myddleton burned down Mathafarn on 29 November 1644, along with a number of houses in Machynlleth.