[1] The Roman road from Londinium (London) to Calleva Atrebatum (Silchester), commonly called the Devil's Highway, crossed the Thames in the Staines area.

[7][8] It is thought that Staines was chosen as the location of the crossing, because the gravel islands in the area constrained the main river channel so that it could be bridged.

[9] There was a settlement in the area surrounding the High Street and, although the date of its foundation is uncertain, the earliest archaeological evidence is from 54–96 AD, corresponding to the reign of Nero and the period of the Flavian Dynasty.

[7] However, more recent excavations have revealed that the width of the Thames at this point was around 230 m (250 yd) in Roman times, which may have been too wide for a bridge of that period, leading to the alternative proposal of a site closer to Egham, possibly as far upstream as Church Island.

[9] The first surviving mention of a bridge from the medieval period is a document from 1222,[8] that authorises repairs using wood cut from Windsor Forest.

In around 1250, a causeway was constructed at Egham Hythe to improve the southern approach to the crossing[10][a] Also during the 13th century, there were renewals of the grant of pontage and, in 1376, tolls were levied on boat traffic to provide additional funds for maintenance.

[10] Local people left bequests for not only the repair of the bridge, but also for the upkeep of the roads leading to it on each side of the river.

2. c. 25) noted that the structure was "in a ruinous and dangerous condition" and that the money raised from tolls and local taxes was insufficient to fund adequate maintenance.

[14] The artist, J. M. W. Turner, produced a sketch of Sandby's bridge when it was under construction, which was subsequently turned into an engraving by John George Murray.

[14][3] Rennie insisted that the site of the crossing be moved upstream of the confluence of the Colne and Thames, where deeper foundations could be constructed.