The Pipe rolls contain accounts of the royal income for each financial year. They are arranged by county, and between the 12th and 19th centuries, there is almost a complete set. It is so called because they are sewn together in a way that makes them look like pipes when rolled up.
The earlier roles are a useful source of information as there were few other records dating from that time. Indeed, it is from the pipe rolls that we have got the first recorded names of many of the villages in the villages section of the site. These were formed from the sheriffs' accounts, the sheriff being the kings representative in each county. They include information about taxes, feudal dues and penalties.
For more information, please visit the Medieval Genealogy website: Medieval Genealogy, Public Records: Pipe Rolls.