Stane Street is the modern name of the 91 km-long (57 mi) Roman road in southern England that linked Londinium (London) to Noviomagus Reginorum (Chichester).

Several parts of Stane Street are listed as scheduled monuments, including the well-preserved section from Mickleham Downs to Thirty Acres Barn, Ashtead.

[8] Archaeological evidence from later periods includes coins from the reigns of Titus (79–81), Domitian (81–96), Nerva (96–98),[8] Hadrian (117–138), Commodus (180–192),[9] Severus Alexander (222–235),[10] Gallienus (260–268),[11] Claudius Gothicus (268–270)[9] and Constantine the Great (306–337).

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.

[14] 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.

[16] 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'.

[17] Near to the Alfoldean station the metalling was constructed from iron slag in a solid 30 cm-thick (1 ft) mass, topped with a double layer of sandstone slats.

[20] Posting stations or mansiones were provided at regular intervals (generally every 15–20 km (9.3–12.4 mi)) along Roman roads, so that official messengers could change horses and travellers could rest.

Cremation burials dating from the late Iron Age and early Romano-British periods have been found both inside and just outside of the enclosure, however, their relationship to the rest of the mansio is unclear.

[9] The northernmost section of Stane Street, from London Bridge to Ewell, is the only part of the road which lies on the direct alignment to the east gate of Chichester,[30] (although the builders made short local deviations to avoid difficult ground conditions).

[33] From there the route heads southwestwards, but between Borough and Elephant & Castle tube stations, it deviates from the direct line to Chichester to run along Newington Causeway, most likely to avoid marshy ground to the east.

[16] The course of the river has changed since Roman times and the original crossing point (believed to have been a ford, although there may have been a bridge for pedestrians) was close to the site of Colliers Wood tube station.

Close to the present Church Street, the road makes a 23° turn to the south, to allow it to reach the Upper Chalk of the North Downs more quickly.

[17] It has been suggested that the road bends somewhat more sharply than was strictly necessary, possibly to avoid the Hogsmill Spring, which may have held religious significance for the local British tribes.

[17] A 2020 Lidar survey revealed that Stane Street was built across an earlier field system, although it is unclear whether the area was under active cultivation at the time of construction.

[45] Although no conclusive evidence for the route has been found in the 5 km (3 mi) 'gap' between the Mole crossing and North Holmwood, Stane Street is thought to have passed through Dorking which was a Romano-British settlement.

[9] In the 1960s, the historian Ivan Margary proposed that the road headed directly for the town centre from the Burford Bridge, an alignment that would have taken it beneath the present day Ashcombe School site.

[51] Numerous excavations and chance findings along the length of the High Street (from Pump Corner in the west to Pippbrook House in the east) have produced coins, pottery sherds and other items that indicate a Roman presence.

[50][62][63] Much of this section remains in good condition (albeit buried below ground level), although the upper surface appears to have been removed (presumably to supply stone to local building projects).

[77] Through Eartham Woods where the Monarch's Way long-distance path follows the route, the flint surface of the well-preserved road is exposed and the trees are mostly cut back to the boundary ditches.

[76] The A285 joins the route at the western side of Eartham Woods, although it leaves the alignment almost immediately to avoid the ascent of Halnaker Hill, before rejoining again for the final 7 km (4.3 mi) stretch into Chichester.

[78] It has been suggested that the section of road between Chichester and Hardham was the first part of Stane Street to be constructed and that (based on archaeological finds) the Romans straightened and improved an existing Iron Age trackway.

The London to Brighton Way road diverged at Kennington Park, before passing through Croydon, Godstone, Haywards Heath and Burgess Hill to cross the South Downs at Clayton.

The mansio at Hardham is thought to have become disused by the end of the second century AD and the road is absent from the third-century Antonine Itinerary, which indicates that the preferred route from Chichester to London was via Winchester.

[3][20][16][note 5] Nevertheless, Stane Street continued to be an important trade route until at least the early fourth century, and goods transported along the road included pottery from Rowlands Castle.

Although Londinium had been abandoned as a city by the fifth century, the sphere of influence of its successor, Lundenwick, was sufficiently large to ensure the retention of the stretch of road between Ewell and Southwark.

[note 6] The emergence of Sussex as a political entity, decreased the importance of the north-south roads leading across the Weald to the former Roman capital and so much of the rest of Stane Street was abandoned.

Particularly where the route ran across Weald Clay, removal of the upper surface probably rendered the road unusable in the wetter months and subsequently all traces were eliminated by ploughing or urban development.

[61] Daniel Defoe (the author of Robinson Crusoe) described the disappearance of Stane Street in his travelogue, A tour thro' the whole island of Great Britain (1724–1727), which describes the country shortly before the start of the Industrial Revolution: Although knowledge of Stane Street appears to have continued from Anglo-Saxon times into the early modern period and beyond (as evidenced by a reference in Britannia by William Camden, first published in 1586[91]), no systematic studies of the route were carried out until the early 20th century.