Kenfig stood by the edge of marsh land hence its original Welsh name 'Cefn-y-ffignon' (a corruption meaning 'a ridge on a marsh') - Thomas Gray who wrote the book 'The Buried City of Kenfig' 1909 maintained it was Cen-y-fig, 'head of the swamp'.

The Welsh lord Iestyn ap Gwrgant had been the owner of this land but was defeated by the Norman conqueror of Glamorgan, Robert Fitzhamon who built a motte and bailey castle here to defend the area. The town of Kenfig was then developed by the Normans with the deliberate intention of making it a trading centre of Mid Glamorgan - 'A towne for merchandize upon the sea bankes of Kynfege'. Kenfig had an outlet to the sea most probably via the Kenfig River.

Kenfig suffered badly from the raids of the disinherited Welsh Lords of Afon especially Morgan Gam. It was burned down so often that the inhabitants built a stockade around the perimeter of the town only to have it struck by lightening and burnt down again.

Even the great Llewelyn had a go at it leaving the place in ruins and later Ownain Glyndwr destroyed it. Each time the town was rebuilt but as time went by the enemy became not the Welsh but sand. A series of great storms beginning about the year 1300 followed by long periods of drifting sand slowly made life impossible for the inhabitants and by the end of the 15th century it was a ghost town. In the 16th century it was nothing more than 'a little village on the east side of Kenfik and a castel booth in ruine and almost shokid and devourid with the sandes that the Severn Se there castith up'.

Kenfig was a town of some importance in the middle ages. By a charter its burgesses were allowed to levy their own taxes and make their own bye-laws.

The town had a high street which had to be kept clean, a guildhall and even a hospital. They had strict ordinances about food and drink - brewers must brew good ale and bakers good bread. Weights and measures were carefully controlled by correct master-measures.

'Noe manner of person shall paly at dice, cardes, bowles nor other unlawful games' - 'If six men find any woman guilty of scolding or railing, she was to sit on the cucking (ducking) stool one hour and for the second fault two hours...' They had the right to hold fairs and the big event was the mabsant, the annual holiday on Saint's day, kept in November, for their patron and benefactor was St. James, after whom the town's buried church had been named.

Nearby were the marshes - the great storms of the 14th century threw up a surrounding ridge of sandhills and the marsh gradually became a lake between 70 and 80 acres about 1000 yards from the sea shore. The water is fresh from springs and there must be some sort of drainage under the continually moving sand.