british population data
© A group of young evacuees sit on a hay cart outside Chapel Cleeve Nursery in Washford Somerset
Stored for 76 years in a government building in Lancashire, the files include metadata covering 41 million people

In a move that will transform the study of key aspects of 20th century British social history, one of the country's most important data collections is being made available to historians and the general public from 2 November. Historical researchers have for the first time digitized and placed on-line a detailed survey of English and Welsh society at the beginning of World War Two.

Stored for the past 76 years in a government building in Southport, Lancashire, it includes metadata covering 41 million individuals (with personal information publicly available on 70% of them) and fills a major 'knowledge void' about British social history in the mid-20th century. In terms of detailed digitally available metadata, it is the only major source available for the 1920s to 1940s era - while, in terms of accessible personal data on millions of named individuals, it's the only publically available source for most of the 20th century.

The only other similarly detailed 20th century sources for personal information about millions of individuals are the 1901 and 1911 census records which were only made public in 2002 and 2009. Under the UK's '100 year rule' privacy convention, post-1920 census information about individuals must remain confidential for a full century after the data was collected.

But the information, being made available online on 2 November by a major British family history company, Findmypast, in collaboration with The National Archives, is not from a census - because it was gathered as part of a nationwide compulsory registration campaign at the beginning of World War Two.
british population data
A group of children arrive at Brent station near Kingsbridge Devon after being evacuated from Bristol
Even more comprehensive than a normal census (in terms of the number of people covered), the 1939 'Register' was designed to enable the government to distribute identity cards and ration books and to facilitate conscription. Failure to register was illegal. An army of 65,000 official 'enumerators' collected the personal details of 41 million people. Only a tiny number of tramps, criminals and conscription-dodgers slipped through the net.

A similar operation occurred in Scotland and Northern Ireland - but it has so far not been possible to make all that material publically available.

Because it wasn't a census, the normal '100 year rule' does not apply to the 1939 registration operation in the same rigid way that applies to census records. Instead, the UK Information Commissioner decided that the details of any individual on the England and Wales 1939 Register who had been born more than 100 years ago or had died since 1939 (a grand total of 28 million people) could be released. His decision effectively also meant that all the metadata covering all 40 million individuals could be released in its entirety.

british population data
A Day in the Life of a Wartime Housewife, London, England
From 2 November, members of the public will now be able to have access to full details about their parents, grandparents or great grandparents who were alive and living anywhere in England or Wales on 29 September, 1939. Social historians and others will also be able to interrogate the data at a national, regional, local or even street level.

"The 1939 material is important because it gives us a detailed snapshot of the people of England and Wales, both as individuals and communities, at the beginning of the Second World War," said Audrey Collins, a leading family history specialist at The National Archives.

The data consists of all 40 million individuals' names, date of birth, address, gender, employment status, job and marital status. That information can be accessed for 28 million individuals - or, in metadata form, for all 41 million.

It is free for people anywhere in the world to search for their 1939 register ancestors online on the Findmypast website - and £6.95 to then see that individual's details plus local maps and demographic statistics from 1939. The maps are an essential part of the background information - because, during and after World War Two, literally thousands of urban streets disappeared and no longer exist.

The newly available data reveals a snapshot of what England and Wales was like at the beginning of World War Two. The data shows that the average age for men was 33 and for women 35 (compared to 38 and 40 today). Extreme old age was very rare. Out of the 41 million people, only 111 were aged 100 or more - compared to more than 12,300 today.

The data also reveals that 46.2% of the population was married and that 6.5% had been widowed - but that just 0.1% was divorced. Today 37% of the total population is married, 5.6% widowed and 7.2% divorced.

The statistics also illustrate dramatically how people's working lives have changed - especially for women, with over 70% of working age women in 1939 performing domestic work, most of it unpaid as housewives. There were more than 9.3 million women described as carrying out "unpaid domestic duties" - with 581,000 more working as live-in or paid domestic servants or cleaners.

The survey also casts new statistical light on the evacuation of children at the beginning of World War Two. It reveals that by late September 1939 (less than a month after the outbreak of war), London had become a predominantly childless city. Whereas children under ten made up 14% of England and Wales' overall population, in London the figure had dropped to just 2%. The 10-20 age group population was also much reduced with the capital having just half the national average.

The newly released survey is of additional importance because it was the only national survey of England and Wales' population carried out between the census of 1921 and the that of 1951. That is because the 1931 census data was destroyed in a fire in 1941 - and because the census operation scheduled for 1941 was cancelled due to the war.