Obviously a town on a river needs a number of river crossings, Clopton Bridge is one of several at Stratford crossing the Avon and dates from where the river was forded back in Saxon times and earlier. The first mention of a bridge dates from 1235, later writers considered this bridge a rather poor wooden one that was rather small and could be swamped by the river when waters were high.
The current bridge was built by Sir Hugh Clopton, a "Warwickshire man to the backbone"[1] who also invested in a number of other buildings in the town such as the Guild Chapel and New Place (which later on was where William Shakespeare died) and later became Lord Mayor of London, during the reign of Henry VII in 1480[2]. The bridge has 14 arches though some were widened later to better allow for the passage of boats, a toll house tower also being added. The bridge was widened in the early 19th century due to increasing road traffic. Nowadays the A3400 runs over it.
Parts of the bridge have had to be rebuilt at various times. During the English Civil War for example one arch was demolished, the bridge also had to be partially rebuilt after damage during a great storm and flood in 1588.
[1] John Burman, Old Warwickshire Familes and Houses (Birmingham: Cornish Brothers Limited, 1934), p. 11.
[2] Philip Styles (editor), "The borough of Stratford-upon-Avon: Introduction and architectural description." A History of the County of Warwick: Volume 3: Barlichway hundred (1945): 221-234. British History Online. Web. 01 February 2012.