The Protestation Returns are the closest record we have to a census from 1642. If you can trace your ancestors back to 1642, and you know which county and parish they lived in, it may be worth looking to see if their names are in the Protestation Returns.
By order of the House of Commons, all adult men were asked to swear an oath of allegiance to the Protestant religion in 1642. Their names were duly inscribed in a list in each parish, and the list sent back to Parliament. In a few areas such as Cornwall, people wrote their own names, but usually a local official wrote out all the names. The Protestation Returns survive for about a third of English counties.
Tracing Protestation Returns in the Parliamentary Archives
You can search our online catalogue Portcullis for the Protestation Returns. Enter 'protestation returns' in the Any Text field, and '1641-1642', in the Date field to bring up a list. They are arranged by county, with the parishes or hundreds listed within. Make a note of the references for the county you are interested in, and contact us to make an appointment to see the files or order copies.
If the Parliamentary Archives does not hold any protestation returns for your county, you could try your local county record office in case any were kept locally. Also it may be worth you contacting your local history society, as some have transcribed and published their own Protestation Returns. The following very useful publication describes all surviving Protestation Returns and their location: 'The Protestation Returns, 1641-1642, and Other Contemporary Listings', compiled by Jeremy Gibson and Alan Dell (Federation of Family History Societies, 1995).