This page links to documents [in Adobe PDF format] providing documentation on the history of Pirton. Some may be large: the link will tell you the size.
You can download the following series of articles.
Christopher Dyer 1997, History and Vernacular Architecture
JE Cussans 1874 History of Hertfordshire, containing an account of the descents of the various manors; pedigrees of families connected with the county; antiquities, local customs &c: half Hundred of Hitchin.
N Salmon 1728 The history of Hertfordshire; describing the county and its ancient monuments.
The first free online copy of Domesday Book