Manorial records can be useful sources of information in the period prior to the start of parish records in the 1500's. It is not genearally realised that these courts were still operating into the 20th Century and can provide useful extra information to the other usual sources.
There are many Manorial courts in Cumbria, thier jurisdiction does not in general conform to parish or county boundaries and you can have several Manors in one Parish or parts of different Parishes in one Manor.
The three main Manors in Cumbria are :
Manorial records do not contain details of births, marriages or deaths as such, but they do contain the details of how property was handed over to decendents so often give relationships between people. The attendance (call) lists for the meetings will also detail who owned which property and will show details of people that have recently died. Though these meetings were not always held annually and it could sometimes take several years for the details to be recorded.
Cumbria was divided into superior baronies and superior lordships. These were where several manors were under the control of a single owner and although they may have had thier own courts, they reported to the more senior court of the baron or lord. The Lancaster University site has a useful map of the county and how it was split up at Map of Baronies and Superior Manors of Cumbria
Cumbrian Manorial Documents are described in detail on the Lancaster University site Lancaster University Manorial Records and going through this site will give you a good understanding of what manorial records may contain.
The Manorial Document Register is located on the National Archives site at Document Register, This will give you a list of the documents that are available and where they are located, but it will not let you read the actual documents, for that you must visit the appropriate centre.
If you are interested in Manorial Documents then join the National Archives Manorial EMail list by emailing firstname.lastname@example.org