The ancient port of Porlock Weir has existed for more than a thousand years, having been documented in the Anglo-Saxon Chronicle. Over the centuries it has played a vital part in the life of eastern Exmoor, being one of the few places along the rugged Exmoor coast capable of providing a haven for small craft. Given its isolated position within Exmoor, this sea route was also the easiest way to and from the area. In the 18th and 19th centuries the main exports were flour and corn, bark for tanning, bricks, pit-props for the Welsh coal mines and oysters to Bristol. Imports included limestone and coal from Wales, which were used to make lime in local kilns.
The harbour and much of the surrounding area is part of the Porlock Manor Estate, which has been linked to the Blathwayt family since 1686 when William Blathwayt, Secretary of State to King William III, married Mary Wynter. Porlock was one of the Somerset manors left to Mary and has since passed down the Wynter-Blathwayt line.