The written history of the village starts in Saxon times, though it is believed that there was an earlier Roman settlement, probably a coastal fort. St Felix brought Christianity to East Anglia and established a bishopric here in 630AD. The village grew at the mouth of the river Blyth, then two miles south of the present mouth, and was described in the Domesday Book (1086). The next two centuries brought very rapid growth on the strength of the best harbour in the region, thriving trade with the continent and as far afield as the Baltic, a big fishing fleet, and all the local industries, like shipbuilding, to service them. By the late 1200's, Dunwich had a population of over 4,000, making it the sixth largest town in England, eight major churches, three monasteries, two hospitals, a large market and a Charter from King John.
The sea has been eroding our soft cliffs for thousands of years and played the major role in the prosperity and then the destruction of the medieval town. A horrendous storm in 1286 destroyed part of the town but more significantly filled the harbour with millions of tons of shingle making it unusable for seagoing vessels and overnight eliminated the economic basis of Dunwich. The population rapidly dwindled and over the succeeding centuries the sea has eroded some half mile of cliff. Almost all the medieval town is now offshore, and the seabed is scattered with the remains of the old stone and flint churches.
Politically the town retained its importance, and continued to elect two members to Parliament until the 1832 Reform Act, it was a classic Rotten Borough with at one period just 12 electors for 2 MPs. Control of what was now a village was fought for between outside landowners, the Downing, Vanneck and Barne families, the latter finally owning most of the village and building a fine house for themselves here. The Barnes controlled the village for around 150 years, accounting for the consistency of architectural style found here, and were regarded as progressive and benevolent landlords. The estate was finally sold off and broken up in 1947.
The full story of Dunwich's extraordinary past can be found in the village Museum.