The fields around Dedham contain a large amount of cropmarks, thought to be prehistoric or Roman in date. Prehistoric finds have also been recovered from in and around the town. The place-name of Dedham is Saxon in origin and the Domesday Book confirms the presence of a small settlement at the end of the Saxon period (Rumble, 1983).
Medieval Dedham was largely a one street town, the High Street, the market-place being formed from a widening of this street. The Domesday manor of Dedham appears to have been sub-divided in the medieval period to form three separate manorial holdings (Dedham Hall, Overhall and Netherhall). All of these owned property in the town. Dedham rose to prominence with the cloth trade, specialising in bay and say cloth. This industry seems to have started in the 14th century, and there are documents dating to the time of Edward III recording the arrival of Flemish weavers. It reached a climax of prosperity in the 15th century, before going into decline and eventually dying out in the 17th century. In the early post-medieval period the economic life of the town was depressed as a result of the demise of the cloth-trade, although there was still a cottage industry in the spinning of woollen yarn and the knitting of stockings. The town had a minor resurgence in the 18th and 19th centuries as a social centre for the local gentry, on account of the grammar school and the Assembly Rooms. The tourist trade forms a major part of its current economy.