Llansteffan Castle stands on a headland overlooking the sand-flats of the mouth of the river Tywi.
The natural strength and strategic importance of this stunning location was recognised by the Norman invaders of Wales who established an earth-and-timber enclosure, or 'ringwork', within the ancient defences of an Iron Age fort.
The castle controlled an important river crossing and it changed hands several times during fierce fighting between the Normans and the Welsh. The transformation of the early earth-and-timber stronghold into the powerful masonry castle visible today was the work of the Camville family who held the castle from the late twelfth to the early fourteenth century.
The castle was held briefly by Owain Glyndŵr’s supporters in 1405-06. At the close of the fifteenth century, King Henry VII granted it to his uncle, Jasper Tudor, who was probably responsible for blocking the great gatehouse passage to create additional accommodation.