On September 29th 1939, just 26 days after Britain declared war on Nazi Germany, 65,000 enumerators descended on every household in England and Wales to document the lives of over 41 million people in the 1939 Register.

This "Wartime Doomsday book" is the only surviving record of the civilian population of England and Wales between 1921 and 1951. With no 1931 census (it was accidentally destroyed by fire unrelated to enemy action during the Second World War) and no 1941 census (Britain was in the throes of war), the 1939 register bridges an essential 30-year gap in history and provides an incredibly rare snapshot of a vanishing Britain.

The sheer scope and scale of what was recorded by the register means that it is an incredibly valuable resource for social historians looking to gain a better understanding of the makeup of interwar Britain. The register differs to censuses in the level of detail collected. Occupations were recorded in great detail so that the Government would be able to identify trades and skills that would be useful in the war effort. Precise dates of birth are also given in full, whereas census returns only give the person's age.

Using the register to examine various regions of the country can make for some very interesting comparisons. In order to do this, you can either search for a specific town or address or you can try searching by registration district. First off, you will need to access the advanced search screen by clicking on the button in the top right hand corner of the quick search box.

Click the 'Advanced search' button in the top right hand corner of the search box

From here you can search for a household or institution using our dedicated address search. To access this page, select "Address" using the Person/Address tabs found at the top of the page.

Our dedicated 1939 address search page

An address search allows you discover who was living at your house in 1939. Such a search is particularly useful for those interested in the history of a specific street or area as searching by street/road name will bring pull out results for every household registered to that address. Examining the records of the various inhabitants and their occupations will give you a good idea of the make of local population, such as whether the area was primarily working class, whether it was home to large numbers of retirees or agricultural laborers , and so forth.

Watch: Andrew Marr introduces life in 1939

While exploring the register, be sure to examine the wide array of supporting content included on each transcript page. Each contains a wealth of contextual information, including period photographs, infographics, region-specific newspaper articles and historical and contemporary maps, all personally tailored to each record.

The infographics display statistics based around the common surnames, population sizes, household sizes, gender ratios, age ranges and common occupations within that particular district or borough. They also show the corresponding figures for England and Wales as hole and comparing the two is a great way of finding out how your local area measured up against the rest of the country. In order to view the infographic for a particular region, start by filtering your search by registration district using the browse borough/district form on the search page.

You can filter your search across as many registration districts as you want

The Register covered over 1400 enumeration districts that were split into four categories; Rural Districts, Urban Districts, Municipal Boroughs and County Boroughs. Rural and Urban districts tended cover smaller local areas while County and Municipal boroughs covered entire counties and local government districts.

Once you have selected the district or county you are interested in and added it as a filter, perform a blank search and view one of the results. After opening the transcript, scroll down the page and below the transcript box itself you will find the first piece of regional information in the form an ONS map of the area.

A contemporary ONS map of thhe City of Westminster

You can then use the drop down menu in the top left hand corner of the map to switch between maps of the same area from 1889-1913, 1937-1961 and the present day. Click and drag your cursor to navigate the map and use the small +/- button to the left of the drop down menu to zoom in and out. Comparing the three maps allows you to see how the area has changed physically over the past 128 years.

Present day map of the City of Westminster

Continue to scroll down the page and you will reach the first of four infographics.

Population size and the most common ten surnames within the Rural District of Selby in North Yorkshire

Using the information recorded by the original register, this infographic displays the total population size of the district in question and the 10 most common surnames of its inhabitants.

Using the tabs at the top of the infographic, you can then view the corresponding figures for England and Wales as a whole to see how the two measure up.

Corresponding figures for England and Wales

The second infographic, accessed using the arrow buttons in the bottom right hand corner, displays the average modal household size and the total number of households within that district. When comparing various districts you may notice that poorer, more urbanised regions will tend to have higher counts than those in more affluent areas.

The third and fourth infographics make for perhaps the most interesting comparisons. Infographic three reveals the male/female population split as well as the number of individuals in each ten year age bracket from 0-9 to 80+. You may notice that areas with high levels of heavy industry tended to have larger male populations as well as higher numbers of inhabitants between the ages of 20 to 40. Infographic three is also a great way to see how evacuation changed the make up of Britain's cities and industrial regions as just 2% of the population in London was aged 0-10, compared with the national average of 14%, while 8% was aged 10-19, against 16% nationally.

Infographic four lists the top ten occupations for men and women in that region. Comparing this against the national average or against other districts will reveal the nature of the local economy. For example, comparing the results for the rural district of St Austell in Cornwall against those for England and Wales as a whole shows how the china clay industry was one of the main sources of employment for men in region as three of the top ten most common occupations were related to clay production.

Three, possibly of the top ten male occupations in St Austell were related to Clay production

Top ten male and female occupations across England and Wales.

Explore Britain in 1939