Runcorn is an industrial town in the borough of Halton and the ceremonial county of Cheshire, England. It is located on the southern banks of the River Mersey at the site of the river's first bridge crossing. The name came from Saxon Rumcofan = "wide bay or creek". At nearby Norton Priory, there are old maps showing a settlement with the name Wronkhorne.
In Norman Cheshire, the first Earl of Chester, Hugh d'Avranches split his estate into baronies. The Halton barony held precedent over all others and Nigel, the constable of Chester (Cheshire) became its first baron. Nigel erected a motte and bailey castle on Halton Hill around 1071 to keep watch over the Lancashire and Cheshire plains and the river estuary. The stone structured castle, as is seen remained today, would have started development in the later half of the 12th century; being gradually built upon, with each of the early barons undertaking various projects and adding to the work of his predecessor.