When it’s March and the year has a ‘1’ at the end, I am usually pretty busy because it’s time for the decennial census in the UK and because I’ve become the ‘go to’ person for journalists who want to know about the history of the census.

This year however, I also got another request, from a very different audience. Year 8 students from Radyr Comprehensive School in south Wales wanted me to answer their questions, and it turned out to be a very enjoyable experience.

Why they wanted to talk to me

The Q&A with Radyr Comprehensive pupils was organised by the Cambridge University Group for the History of Population and Social Structure (CAMPOP).

The Radyr pupils had already been working with CAMPOP’s Populations Past interactive map of England and Wales, 1851-1911 which shows England and Wales, divided into cells representing registration districts, which are then populated with historical data on births, marriages and deaths, and census data, for each of the census years from 1851 to 1911.

The census data was taken from the Integrated Census Enumeration Microdata (I-CeM) dataset, which I helped to create. This is one of the world’s largest historical dataset, containing approximately 20 billion data points relating to all individuals in the manuscript censuses of the period.

The Populations Past map allowed the children to examine changing fertility, mortality, age structure, women’s work, and so on, over time and by place.

What they wanted to know

The Year 8 students had a lot of questions, many more interesting than those I am typically asked by journalists! These were their top questions, and how I answered them.

How did you get involved in studying the censuses of the nineteenth century?

My own introduction to the Victorian and Edwardian censuses came as a result of doctoral research at Oxford in the 1970s, and my later career as an archivist in the National Archives, where I was responsible for making the census returns available to the public.

How has the census changed over time and has it become easier to complete?

My replies to these two questions were linked because one of the reasons for the expansion of the number of census questions over time has been the increasing ability of people to answer them.

When most people could not read or write very well, if at all, the government had to limit the amount of information to be collected. As literacy increased after the introduction of compulsory education in the 1870s so did the number of questions, in line with the state’s new interests in economic conditions, family size, wealth, and personal identity.

What is the most important finding from the census during the timeframe you study?

Perhaps the most important result to come out of the Victorian census, indeed any census, was the realisation in 1851 that for the first time in world history, Britain had become a society in which the majority of people lived in towns and cities, rather than in the countryside.

The density of people in these urban spaces also created a public health crisis, with pandemics such as cholera caused by the sheer amount of human excrement in the environment.

What has changed as a result of census taking?

The measurement of that density by the 1851 census, and mortality rates based on it, helped to fuel the great Victorian sanitary movement, which cleaned up the cities and began the subsequent doubling of life expectancies we enjoy today.


The census is a huge data-crunching exercise, but it’s also full of small, individual insights and stories about people’s lives, and that makes it terribly interesting. Speaking to the Radyr Comprehensive pupils was enlightening and enjoyable.

Listen to the Q&A with pupils from Radyr Comprehensive School.

Find out more about the Integrated Census Microdata (I-CeM) Project.