Archaeology suggests that a Northampton settlement began as early as 4000 B.C. where evidence has been found in the Briar Hill area. This manifests itself as a circular earthwork in which the inhabitants would gather socially and/or religiously.

Circa 2000 BC Bronze age settlements are in evidence with pottery and light weapons being found scattered in various areas of the county in the form of arrowheads and axes. The people would largely have lived in 'roundhouses' made of earth and timber.
Quite sizable farm settlements from the 1000 BC also appear throughout the southern valley areas of the county.
During the Iron Age at around 400 BC there is also evidence of a fortification at Hunsbury which consisted of a mound of defensible earth whose shape can still be made out to this day. It is thought that this settlement was used until around 20AD with pots and tools being found during this time period.
Other, smaller hill forts may also have existed at Rainsborough, Badby, Thenford, Borough Hill, Castle Dykes, Guilsborough, and Irthlingborough.
Most people of the Iron Age were farmers, merchants, or craftspeople living in tribal communities although there seems to have been a need to protect themselves with these hill forts. This may have been during times of war but more likely on a daily basis to protect themselves and their livestock from predators such as boar and wolves.
Northamptonshire was heavily wooded and would have been a rich farmland. The tribes would live near natural resources such as atop hills for protection, but also near rivers and woods for growing food, raising livestock and hunting.
The hill forts themselves probably consisted of a small group of houses which were a stone, circular wall about 4 feet high with a thatched pointed roof. These houses were surrounded by a wooden palisade situated on top of a steep bank. In some cases a ditch may be dug at the bottom of the bank.
It is likely that a local chief would live in such a enclosure with his family and warriors with the regular tribes-folk living in the area surrounding it. During dangerous periods the tribe would gether inside the walls of the fort and take their sheep and cattle with them.
This strong tribe occupied the central part of England, encompassing London, Hertfordshire , Bedfordshire, Buckinghamshire, Cambridgeshire, Oxfordshire, parts of Essex and of course Northamptonshire.
When the Romans first came to Britain in 56 BC this tribe were the most dominant tribe in Britain having conquered much of South East England. We know that their leader, Cassivellaunus, organised the resistance against Caesar's second expeditionary force (55 BC) and whilst the Roman journals do not mention this tribe too much, it is suspected that this is because they caused Caesar a good deal of trouble and as such, the Romans (the self promoting Caesar in particular) were not keen to document this.
This tribe also appear to be using excellent miltary tactics to gain control of a large areas of south-central England to take advantage of trade and political oppurtunities. Caeser himself remarks on the use of skilled charioteers who at that time had never been part of a Roman army.
Cassivellaunus was finally defeated in 54 BC who was forced to surrender after he had dismissed most of his army relying on guerrilla tactics to outmanoeuvre his larger foe.