A woman's place used to be in the home – women gave up work after marrying, and husbands were the breadwinners. That's what we have long believed. The very idea that a woman would hold down a job, while leaving her children in a creche or with a childminder while she was away at work is new and modern – a result maybe of wartime changes, or the liberation of women since the 60s, and certainly not the norm in Victorian Britain. Like many things that everybody knows, however, this picture is inaccurate. Research I have undertaken shows that women have traditionally worked in a much wider range of occupations than previously thought – many of them today regarded as men's work – and were frequently the main earner in their household.

During the course of my research into Victorian families I have been told again and again that it was rather strange to be researching married women's work, as married women didn't work. It was interesting to move beyond the academic and the general, and to find my own great-grandmother, a formidable woman who was firmly of the opinion in later life that a woman's place was at home, being recorded in the census as a juvenile suit-maker and her mother also working, as an umbrella-maker.

This research has ramifications beyond the historical and academic and has implications for policymaking. It can be suggested that what we "know" to have been the family norm for centuries is little more than an aberration from the norm that has lasted less two generations.

The image of the "angel of the house" was very much a middle-class ideal and not a working-class reality. For most women, the luxury of being a housewife, simply caring for children, cooking and cleaning and creating a peaceful haven for the hard-worked husband who brought home the bread at the end of the day, was only ever an illusion created by the middle classes. Economics dictated that not only both parents but in most cases the children as well needed to work. Indeed, even our belief that the decline of the "job for life" is a modern issue couldn't be further from the truth. For vast numbers of working-class men a job was something that you did while it was available, and your wages were not in any way reliable.

Over the course of five years beginning in 1849, Henry Mayhew, a writer for the Morning Chronicle, laid bare for his readers the reality of working life for the poor in London. He described how something as simple as the wind blowing from the east for a few days would put more than 20,000 dock labourers out of work, along with all others whose livelihood depended on the river – the same situation holding true for all of the other ports around the country. A rainy day in London would deprive close to 200,000 men of an income. This was an age before sick pay, before a salary – no work equated to no pay. This is before we consider the seasonal and casual nature of work in Victorian Britain – where the weather, fashion and the seasons all created a situation where in some months work was available, in others hours would be reduced, or lost altogether.

The understanding has been that this was a problem that affected only women but this isn't the case – men's work in many of towns and cities was perilous to say the least, and men have been shown in numerous historical sources to move from job to job following a wage.

In Norwich, for example, according to the reporter CB Hawkins, for many migrants moving into the city in search of work, there was nothing stable for men, the only real jobs were for women.

The reality for many working-class families of the 19th century was that it was absolutely essential for the wife to work, and to work hard. The days of the 9-5 were decades away; instead many worked on average 12-15 hours a day, every day, and not just in what we might consider "normal" women's jobs such as domestic service, charwoman, laundress or shirt-maker. The census shows hundreds of different occupational titles for women, including married women working in agriculture, artificial flower-making, chemical working, cigar-making, warehouse supervising, the lithograph trade, meat preserving, straw plaiting, manufacturing of food and drink, printing, rabbit fur pulling and even medical galvanising.

One of the best sources for understanding women's work in the 19th century is through the analysis of the census of England and Wales. Censuses were taken every 10 years and contain information on every man, woman and child in the country. We get a snapshot of life on a given night in every house across the country. We can see where people lived, the household structure of each abode, their ages, where they were born, whether they had any disabilities, their occupations and how many children the family had (again, we find that not everybody had lots of children living in a single room, and how many children you had could depend on where in the country you lived).

One issue that has been raised by historians in the past is that the census isn't a reliable tool for analysing women's work. It has been suggested that the effect of the Victorian domestic ideology – the belief that a woman's place was in the home and that working for wages was unacceptable – would have affected the way in which the enumerators, who collected and collated the household schedules from each property, recorded women's work. They might have thought it unimportant, or not a real job.

Even more convincing was the argument that husbands might have been ashamed to admit that their wives had to work, and that their labour wasn't enough to support their family, and so they left their wife's job off the census.

My analysis of more than 23,000 women to date has shown that this was not the case. There is nothing to suggest that either the enumerators or husbands omitted to mention the women's work. On the contrary, in districts of Norwich, for example, more than 50% of women who are recorded as having a job are married. In towns in East Anglia and in London on average more than 30% of married women are recorded as working, and this matches with what other historical records can show us.

Women had to work or their families would starve. The situation we find ourselves in today where a significant percentage of mothers are working – many actively wanting to work, but for others their employment being a necessity to pay the mortgage and feed the family – is nothing new. The halcyon days of the mid 20th century, where more mothers did stay at home and the father could be a breadwinner, was not the norm for more than a handful of decades. Even as late as 1915 Clementina Black was bemoaning the fact that so many women had to work to keep a roof over their heads, supporting their husbands in bringing home the bacon.

As an upper middle-class woman Black found it pitiful that these women were working, and she spent her life trying to promote women's rights in the workplace, and a fair wage for a fair day's labour. She understood, as did everyone else, that women's labour was central to the family and to the economy as a whole, and not something that needed hiding away or ignoring.

Dr Amanda Wilkinson is a researcher and teacher in the department of history at the University of Essex