To the west of Llanblethian, between Breach and Marlborough farms, tumuli - ancient burial mounds - dating from the Bronze Age have been found.

[2] On Llanblethian Hill is the site of Caer Dynnaf, a large Iron Age fort, whose walls and ditches can still be seen.

The first lord of Llanblethian manor was Robert St. Quentin, a powerful Norman knight who held lands in Wiltshire, Dorset, Essex and Yorkshire.

[6] By the 18th century, Llanblethian contained a few large houses, but was essentially a collection of farms with the economy supported by craftsmen with some emphasis on the weaving trade.

[2] A hundred years later the village had begun attracting wealthy residents, including retired military and naval officers.