Stane Street is the modern name of the Roman road in southern England that linked Londinium (London) to Noviomagus Reginorum (Chichester). The exact date of construction is uncertain; however, on the basis of archaeological artefacts discovered along the route, it was in use by 70 AD and may have been built in the first decade of the Roman occupation of Britain (as early as 43–53 AD).
Stane Street shows clearly the engineering principles that the Romans used when building roads. A straight-line alignment from London Bridge to Chichester would have required steep crossings of the North Downs, Greensand Ridge and South Downs. The road was therefore designed to exploit a natural gap in the North Downs cut by the River Mole and to pass to the east of the high ground of Leith Hill, before following flatter land in the River Arun valley to Pulborough. The direct survey line was followed only for the northernmost from London to Ewell. At no point does the road lie more than from the direct line from London Bridge to Chichester.
Today the Roman road is easily traceable on modern maps. Much of the route is followed by the A3, A24, A29 and A285, although most of the course through the modern county of Surrey has either been completely abandoned or is followed only by bridlepaths. Earthworks associated with the road are visible in many places where the course is not overlain by modern roads. Several parts of Stane Street are listed as scheduled monuments, including the well-preserved section from Mickleham Downs to Thirty Acres Barn, Ashtead.
Etymology
Stane is simply an old spelling of "stone" () which was commonly used to differentiate paved Roman roads from muddy native trackways. The name of the road is first recorded as Stanstret in both the 1270 Feet of Fines and the 1279 Assizes Rolls of Ockley. Some historical sources refer to the road as 'Stone Street'. There is no surviving record of the road's original Roman name.
Dating evidence
A number of first-century pottery fragments have been found along the road, including samian ware of Claudian date at Pulborough. The earliest coins found along the route are from the reigns of Claudius (41–54 AD), Nero (54–68) and Vespasian (69-79), consistent with the road being in use by 60 to 70 AD. Stane Street may in fact have been constructed during the first decade of Roman occupation, as early as 43–53 AD. Archaeological evidence from later periods includes coins from the reigns of Titus (79–81), Domitian (81–96), Nerva (96–98), Hadrian (117–138), Commodus (180–192), Severus Alexander (222–235), Gallienus (260–268), Claudius Gothicus (268–270) and Constantine the Great (306–337).
Surveying
The direct line from London Bridge to Chichester passes over the North Downs at Ranmore ( above ordnance datum) and the Greensand Ridge at Holmbury St Mary ( above OD). The steep gradients that would have been required if the road had followed a direct line would not have been practical for wheeled traffic. The road was therefore designed to cross the North Downs by a natural breach cut by the River Mole and to pass to the east of the high ground of Leith Hill.
The geology of the region was also considered and the road leaves the direct line at Ewell to move onto the well-drained chalk of the North Downs, in preference to remaining on the London Clay. The road is able to make a more gentle ascent of the South Downs escarpment at Bignor than was possible at East Lavington and the chosen route avoids the need to cross the steep-sided River Lavant valley at East Dean.
No evidence survives as to how the course of the road was surveyed.
Design and construction
For much of its length, Stane Street consisted of a central agger (a raised embankment on which the upper road surface was laid), with parallel ditches either side. A variety of local materials was used to build the road, sometimes supplemented with stone brought from elsewhere. The agger was often constructed of alternating layers of sand and gravel paved with large flint nodules, or sandstone, surfaced with smaller flint or sand and gravel. The metalling was generally about thick at the centre and had a pronounced camber.
Around Merton Priory, the surface consisted of sub-rounded flints and gravel embedded in sand and silt. Close to Tyrell's Wood and Mickleham Downs, Stane Street consisted of water-washed pebbles laid directly onto the chalk, which are thought to have given this section its local name, 'Pebble Lane'. Near to the Alfoldean station the metalling was constructed from iron slag in a solid mass, topped with a double layer of sandstone slats.