You are doing some English research in the early 1640’s, and having some difficulty. You say to a friend, "Wouldn’t it be nice if there was a census in 1641". The answer is "Oh, but there is! You should look at the Protestation Rolls." What does this mean?
We need to know a bit of history. King Charles 1 became king on 27 March 1625. He made three fatal mistakes, among others. First, he surrounded himself with powerful favourites, a tactic that had caused problems for kings for over 400 years. Second, he married a militant Catholic, and he wanted to change the Anglican Church and the Scottish Presbyterian Church so that their ceremonies were very similar to Catholic ceremonies. This despite the fact that England and Scotland had spent the previous 75 years fighting wars to avoid Catholic influence. Third, he believed strongly in the right of Kings to do whatever they wanted at the expense of their subjects. This attitude is impossible with a reasonably well-educated and prosperous middle class, as was proved in different form in the American Revolution.
Charles decided in 1630 that he would rule the country himself, and dismissed Parliament. For 10 years, he tried to carry on without using Parliament’s power to levy taxes. Finally, he had to recall Parliament to bail him out of an impossible financial situation. By that time, the members of Parliament were mostly determined Puritan radicals, and their co-operation was bought at a high price, including execution of some of his main supporters, and abandonment of some of the powers he claimed.
One of the first supporters to go was Thomas Wentworth, Earl of Strafford, who was actually a first-class general and administrator. Following rumours that there was a plot by the army to rescue him from the Tower of London, the Puritan House of Commons prepared a sworn oath "to live and die for the true Protestant religion, the liberties and rights of subjects, and the privileges of Parliaments:. The members signed the oath on 3 May 1641. On the following day, the Protestant members of the House of Lords signed, but refused to authorize a law requiring all Englishmen to sign. On 30 July 1641, the House of Commons passed a resolution that those who refused to sign were unfit to hold public office in church or state.
On 4 January 1642, the King accepted bad advice from his wife and one of his counselors, and sent soldiers to seize the five main leaders of the House of Commons. This failed, but escalated the conflict several notches. Immediately, the Protestation oath was printed and sent to the justices of the peace in each county, for distribution to every parish. The oath was read out in every church. Every male over 18 years of age was required to come to church and take the oath in the presence of the vicar and churchwardens. Then, the person signed his name or made his mark. Everyone who refused to sign was recorded on a separate list. The lists were completed by the end of February 1642 and returned to Parliament.
These lists are held by the House of Lords Record Office, and some have been printed by authors, researchers, and Record Societies.
For the genealogist, a list of all male persons over 18 in a parish in 1642 is a major find. It is not as good as a real census, because it does not list females and show relationships. Its main use is in conjunction with other records. For example, if your ancestor William Brown was over 18 in 1642, it is very useful information when you discover that he was the only William Brown in that parish at that time. People often-signed in family groups, Father and sons together, so William’s mark is followed by those of his two eldest sons. The other sons, under 18, did not sign. You therefore have confirmation of some of the age information in the parish registers. And if William signed the Protestation Roll and his Will was probated six weeks later, the fact that you can’t find his burial is not as important in establishing his date of death.
One final point. I mentioned that the King was in financial difficulty in 1640. Parliament allowed him to do a Poll Tax on the wealth of everyone over 16 in 1641, so here is another list, this time of males and females, made in August of that year. Compare the two, and add parish registers and Wills, an you should be close to a complete list of the families in that parish at that time.