It was complied on September 29 1939 and listed the names addresses and occupations of 41 million Britons.
The idea for a national register had been floated the year before and was seen as necessary in the event of a war.
The information it contained was used in the organisation of identity and ration cards and after the war in the establishment of the National Health Service.
That in itself makes it a very important document but more so because it will be another six years before the 1921 census is published.
Added to which there is a gaping hole in what will be available given that the 1931 census was destroyed and the 1941 census was never taken.
And so I was there this morning ready to search for my family.
But nothing is that easy.
I had assumed at first it would be free to subscribers but no it currently can only be accessed by a sliding scale of payments depending on how many householders you want to see.
Undaunted I went ahead grudgingly accepting the argument that the cost had been so great that the charge was necessary.
He described himself as "Building labourer heavy worker" and Nana was down as "unpaid domestic duties."
I had assumed that at least mother would also be there although I knew my uncle had by then been in the RAF for a year and would be elsewhere.
What I was not prepared for was a blocked out line with the message “This record is officially closed.”
Now mother was born in 1920 so she is covered by the 100 year rule which excludes anyone looking at information relating to people born after 1915.
That said there is a chance that I can circumvent the regulation by providing proof of my mother’s death.
We shall see.
In the meantime the entry also offers up details on their neighbours, some of whom I knew and some who have also been blocked out.
Like granddad they were mainly manual workers which provides a snapshot of the occupations of Hope Street and so by extension profile of the place.
Pictures; mother and uncle Roger circa 1939 and Nana and granddad circa 1930s from the collection of Andrew Simpson