The first census for the whole of the UK, except Ireland, was taken in 1801.  The purpose of the census at this time was to obtain an accurate picture of the demographics of the country at a time of war with neighbouring France.  Personal details were not included on this and the censuses for 1811, 1821 and 1831; and the bulk of this early material was destroyed once statistics had been published.

From 1841, the census was collected by the Registrar General, and responsible local people appointed as enumerators.  The form or ‘schedule’ was given to each householder and completed on the appointed Sunday night.  The 1841 census took place on Sunday 6 June, but it was later found out that due to the farming season, many itinerant labourers were missing from the schedules (as they were sleeping rough), and so it was decided that subsequent censuses should be held on a Sunday at the beginning of Spring.  The dates of the 1851-1911 censuses are as follows:

1851 – Sunday 30 March

1861 – Sunday 7 April

1871 – Sunday 2 April

1881 – Sunday 3 April

1891 – Sunday 5 April

1901 – Sunday 31 March

1911 – Sunday 2 April

The 1841 census provides limited information in comparison to future years.  Most notably, the age of adults was rounded down to the nearest 5 years, so that the whole population could be classified into age bands.  Therefore, someone aged 41, 42, 43 or 44 would be recorded as aged 40 (on the basis they were truthful or knew their actual age).
 
Today marks the 125th anniversary of the birth of British artist, L S Lowry, famous for his depictions of northern industrial landscapes and working life, and his matchstick men and matchstick cats and dogs:

http://en.wikipedia.org/wiki/L._S._Lowry

Laurence Stephen Lowry was born on 1 November 1887 at No. 8 Barrett Street, Stretford, Manchester.  The first census record that he appears on is the 1891 census, which was taken on 5 April.  He is recorded as a three year old with his parents, Robert Stephen McAll Lowry and Elizabeth, both aged 33 and both born in Manchester.  Robert's occupation is a Land and Estate Agent Clerk. and the family is shown to be living at the same address as Lowry's birthplace  Below is an extract from the 1891 census:
The next census in L S Lowry's life was taken on 31 March 1901.  He is recorded as a 13 year old schoolboy, with his parents, now aged 43, living at 14 Pine Grove, Rusholme, Manchester.  A domestic servant, Lucy England (aged 20) born in Urmston, is living with the family.  The 1901 census extract is below:
The most recent publicly accessible census taken on 2 April 1911, shows Laurence aged 23 and an Accountants Clerk, living with his parents at 117 Station Road, Pendlebury, Swinton, Manchester.  A domestic servant, Alice Powell, aged 23, who was born in Shropshire, shares their home.  The census extract is shown below:
"We went to Pendlebury in 1909 from a residential side of Manchester, and we didn't like it. My father wanted to go to get near a friend for business reasons. We lived next door, and for a long time my mother never got to like it, and at first I disliked it, and then after about a year or so I got used to it, and then I got absorbed in it, then I got infatuated with it. Then I began to wonder if anyone had ever done it. Seriously, not one or two, but seriously; and it seemed to me by that time that it was a very fine industrial subject matter. And I couldn't see anybody at that time who had done it - and nobody had done it, it seemed."