Until very recently there was little evidence of settlements of the period known as the Iron Age (800 BC-70 AD). Since 1960 a number of sites have been discovered particularly on the Cleveland Hills and at Catcote near Hartlepool. Even more recently in the 1970's sites have been found by aerial photography at Longnewton, Wolviston, Ingleby Barwick and Thorpe Thewles.

The first real evidence of man's activities in the parish were discovered in 1976 as a series of crop marks in a field near the A177 Durham road a little to the north of Thorpe Thewles village. An excavation of the site was done by Cleveland County Archaeology Section in 1980 and has given an insight to the life at that time.

Prior to the finds mentioned above there was little evidence of man's activity in the area. This may be because much of the area was still covered with Forests, which at this time consisted of mainly climax oak and lime. Areas that were cultivated would be the less dense woodlands on the hilltops rather than the more wooded valley bottoms.

The settlement at Thorpe Thewles originally consisted of an enclosure surrounded by a ditch. A bank probably inside the ditch would be topped by a wooden fence or & hedge. This would keep the livestock safe from predators but would not deter armed raiders.

The main house had its own drainage ditch and was quite large made from wooden stakes with interlaced withies all covered with a mixture of clay, leaves, straw and animal hair. This was known as wattle and daub. The roof would be conical in shape, thatched on wooden rafters.

A second phase was very similar but was made of puddled clay with straw and hair bonding with no wood in the walls. The third phase was found to be thoroughly burnt but whether by accident or on purpose cannot be said.

These three phases lasted 70 - 100 years.

Other buildings were found inside the enclosure and the number of buildings increased with time as the settlement expanded. Eventually the settlement had expanded from what was probably a farmstead to a small village.

Evidence has shown that as well as crops such as wheat and barley animals were also kept, cattle and sheep were reared although they were breeds, which are now either extinct or very rare. These animals would provide meat and milk as well as leather, bone, horn and wool. In addition cattle could be used to pull the plough and all the animals would provide manure as a fertilizer. Pigs were also kept and horses similar to the Exmoor pony, which could be used for ploughing or for transport.

Other activities on the site included spinning of wool, manufacture of pottery and metalworking. Milling of the corn required the use of stones known as querns, which would be imported from the Pennines or North Yorkshire Moors.

This settlement appears to have been abandoned at about the time of the Roman occupation of northern Britain unlike many similar sites throughout the country, which were occupied into and beyond the Roman occupation of Britain. It may be that the settlement was abandoned for a more sheltered location in the valley closer to running water, possiblv to the present site of Thorpe Thewles.