Following the siege of Dryslwyn Castle in 1287, a payment was made for cleaning out the town ditch, specified as circa villam. This indicates that there was already a substantial settlement outside the castle before the siege and that it was defended. In 1307, the burgesses of Dryslwyn acquired further lands in Cethiniog, in particular in the demesne of Allt-y-gaer, where the lord settled his 'protection tenants'. The town charters of 1324 and 1355 were confirmed in 1391, with additional letters patent giving the burgesses of Dryslwyn equal rights with those of English boroughs, such as Carmarthen. The Black Death swept through the settlements of west Wales in 1349 and must have affected Dryslwyn. Trade and agriculture were both seriously disrupted throughout Wales. The original early 13th-century Welsh town of the lords of Dryslwyn was taken over and expanded by the occupying royal forces after the siege of 1287 and filled with English immigrants.