Neolithic, Bronze Age, Iron Age and Roman artefacts show that the Berkhamsted area of the Bulbourne Valley has been settled for over 5,000 years.
The discovery of a large number of worked flint chips provides Neolithic evidence of on-site flint knapping in the centre of Berkhamsted.
Several settlements dating from the Neolithic to the Iron Age (about 4500–100 BC) have been discovered south of Berkhamsted.
Three sections of a late Bronze Age to Iron Age (1200–100 BC) bank and ditch, sixteen feet (five metres) wide by seven to thirteen feet (two to four metres) high and known as Grim's Ditch, are found on the south side of the Bulbourne Valley.
Another Iron Age dyke with the same name is on Berkhamsted Common, on the north side of the valley.

In the late Iron Age, before the Roman occupation, the valley would have been within Catuvellauni territory.
The Bulbourne Valley was rich in timber and iron ore.
In the late Iron Age, a four-square-mile (ten-square-kilometre) area around Northchurch became a major iron production centre, now considered to be one of the most important late Iron Age and Roman industrial areas in England.
Iron production led to the settlement of a Roman town at Cow Roast, about two miles (three kilometres) northwest of Berkhamsted.
Four Roman first century AD iron smelting bloomeries at Dellfield (one mile (two kilometres) northwest of the town centre) provide evidence of industrial activity in Berkhamsted.
Production ceased at the end of the Roman period.
Other evidence of Roman-British occupation and activity in the Berkhamsted area, includes a pottery kiln on Bridgewater Road.
 The town's high street still follows the line of the Roman-engineered Akeman Street, which had been a pre-existing route from St Albans (Verulamium) to Cirencester (Corinium).

During Roman occupation the countryside close to Verulamium was subdivided into a series of farming estates.
The Berkhamsted area appears to have been divided into two or three farming estates, each including one or more masonry villa buildings, with tiled roofs and underfloor heating.

The remains of a villa were found close to the river in 1973 in the adjacent village of Northchurch.
The oldest building, made of timber, was built in AD 60, rebuilt using stone in the early 2nd century, and enlarged to a ten-room building around AD 150.
The house may have been empty for a period, reoccupied in the 4th century, and abandoned in the late 4th or early 5th century.

A Roman-British villa, dyke, and temple were found 1.25 miles (2.0 km) NNW of the castle, near Frithesden, at the edge of the Berkhamsted Golf Course.
Excavations in 1954 revealed masonry foundations and tesserae floors.
Together, the villa, dyke and temple form a unique complex, suggesting occupation in the late Iron Age and Roman period.

Two flint and tile walls from a Roman building were found north of Berkhamsted Castle in 1970.
The construction of the castle's earthworks in the Middle Ages may have damaged this building.
Neolithic, Bronze Age, Iron Age and Roman artefacts show that the Berkhamsted area of the Bulbourne Valley has been settled for over 5,000 years. The discovery of a large number of worked flint chips provides Neolithic evidence of on-site flint knapping in the centre of Berkhamsted. Several settlements dating from the Neolithic to the Iron Age (about 4500–100 BC) have been discovered south of Berkhamsted. Three sections of a late Bronze Age to Iron Age (1200–100 BC) bank and ditch, sixteen feet (five metres) wide by seven to thirteen feet (two to four metres) high and known as Grim's Ditch, are found on the south side of the Bulbourne Valley. Another Iron Age dyke with the same name is on Berkhamsted Common, on the north side of the valley.
In the late Iron Age, before the Roman occupation, the valley would have been within Catuvellauni territory. The Bulbourne Valley was rich in timber and iron ore. In the late Iron Age, a four-square-mile (ten-square-kilometre) area around Northchurch became a major iron production centre, now considered to be one of the most important late Iron Age and Roman industrial areas in England. Iron production led to the settlement of a Roman town at Cow Roast, about two miles (three kilometres) northwest of Berkhamsted. Four Roman first century AD iron smelting bloomeries at Dellfield (one mile (two kilometres) northwest of the town centre) provide evidence of industrial activity in Berkhamsted. Production ceased at the end of the Roman period. Other evidence of Roman-British occupation and activity in the Berkhamsted area, includes a pottery kiln on Bridgewater Road.  The town's high street still follows the line of the Roman-engineered Akeman Street, which had been a pre-existing route from St Albans (Verulamium) to Cirencester (Corinium).
During Roman occupation the countryside close to Verulamium was subdivided into a series of farming estates. The Berkhamsted area appears to have been divided into two or three farming estates, each including one or more masonry villa buildings, with tiled roofs and underfloor heating.
The remains of a villa were found close to the river in 1973 in the adjacent village of Northchurch. The oldest building, made of timber, was built in AD 60, rebuilt using stone in the early 2nd century, and enlarged to a ten-room building around AD 150. The house may have been empty for a period, reoccupied in the 4th century, and abandoned in the late 4th or early 5th century.
A Roman-British villa, dyke, and temple were found 1.25 miles (2.0 km) NNW of the castle, near Frithesden, at the edge of the Berkhamsted Golf Course. Excavations in 1954 revealed masonry foundations and tesserae floors. Together, the villa, dyke and temple form a unique complex, suggesting occupation in the late Iron Age and Roman period.
Two flint and tile walls from a Roman building were found north of Berkhamsted Castle in 1970. The construction of the castle's earthworks in the Middle Ages may have damaged this building.
Berkhamsted