Family history fans are celebrating the online publication of the 1841 census for England and Wales.
Queen Victoria and Prince Albert were at Buckingham Palace
The name-indexed census has been made available by subscription-based site Ancestry, which has been working with The National Archives on the project.
The 1841 census is the earliest UK census of real use to family historians - and the last of those available to the public to appear online in full.
The project to digitise the images has taken more than four years.
The great and the good are enumerated along with the general public as they appeared on the night of 6 June 1841.
The young Queen Victoria is at home in Buckingham Palace with Prince Albert and the 29-year-old Charles Dickens, whose Barnaby Rudge was being serialised at the time, is with his wife and children in London's Devonshire Terrace.
The publication means that all the publicly available censuses - from 1841 to 1901 - are now online, featuring a total or about 165 million names.
A census is taken every 10 years in the UK, but prior to 1841 they represent little more than headcounts of the population.
The 1841 census is not as informative as later ones: ages are usually rounded down to the nearest five years, places of birth are not given and family relationships are often unclear.
Another problem is that the returns were compiled in pencil rather than pen, which makes the microfilmed images sometimes difficult to read.
But many amateur genealogists are hoping the pages will reveal valuable facts about their forebears' lives and times and provide the leads that have so far been elusive.
Digitising the images from 1841 presented problems that had not been encountered with the other censuses.
"What was unique about the 1841 was that there were about 40,000 pages which were illegible on microfilm and we found that they were unacceptable," explains Josh Hanna, managing director of Ancestry.co.uk.
"So we sent over a team of people to the National Archives to look at the originals. Around 6% of the pages required special scanning."
Mr Hanna says completing the censuses online means the company, which also operates a pay-per-view option, can move on to providing "other record sets".
But in an increasingly competitive marketplace, with other companies offering similar services, he is not keen to reveal specifics.
"The competition keeps us on our toes as a business and benefits the member," he says.