03/08/2011 08:36 BST | Updated 02/10/2011 06:12 BST

Who Do You Think You Are?

Next week sees the return to our screens of the BBC's hit show Who Do You Think You Are? Now in its eighth series, the concept is simple but absorbing; it follows a celebrity on a journey to trace their family tree. Inevitably it throws up ancestral tales which are comic, disturbing, heart wrenching and downright tragic - it makes for compelling television. Such is its success the format has been syndicated to over a dozen international broadcasters.

WDYTYA not only shines a light on an individual's family fortunes it also showcases the repositories of celebrities' secrets, the UK's network of libraries and archives. And the crown jewel in that network is the National Archives, in my book one of our greatest and yet unsung institutions.

Home to the official archive of England, Wales and the United Kingdom, the National Archives preserves over 1,000 years of public records, making it probably the most significant such collection in the world. Its most famous record is the Domesday Book, completed in 1086 and which provides what is believed to be the first survey of England and Wales. It also holds documents from the central courts of law from the twelfth century onwards, as well as government, family and military records.

Recently, I've joined the ranks of historical sleuths, military masterminds and ancestral chasers in rocking up at the National Archives at Kew, and rifling through reservoirs of records - all in the name of research. Let me tell you, it's utterly addictive.

Researching post war foreign office archives is like stepping back into an early James Bond film. The file you've requested arrives. It's marked Top Secret and you feel just a frisson of excitement as you open up the ribbon-bound document. This becomes your very own mission impossible file. The type written notes from our man in Stanleyville reporting back to London on 'restlessness' in the Congo are clipped and succinct. Letters or memos always begin with the surname only of its addressee. No pleasantries. And once you've opened that file, you're lured into requesting the next file in the sequence... and the next.

The archives take you on a fascinating journey. My search led me to papers about a visit to Kenya by the Queen Mother, consequences of changing tobacco tastes in postwar Europe on East African farmers and a series of papers from 1950 on climate change in Africa. Who knew that conferences were taking place on climate change in 1950?

Browsing through files which date back to the mid of last century, of course, is a bit dull compared to those looking at seventeenth century manuscripts and maps. Decked out in special white gloves so as not to leave any moisture on the parchment, these are the real aficionados of historical research at work. And then there are those on their own WDYTYA journey, researching their family trees. People come from the world over to resolve the ancestral riddle of where it all begins. Over coffee in the café on the ground floor, I chatted with an Australian last week tracing her ancestors who moved to Melbourne at the end of the nineteenth century. Arriving at the National Archives, she was set on exploring unchartered territory for the family.

Perhaps the most revealing aspect of a trip to the National Archives is how fastidious the British have been at maintaining often detailed records both here in the UK and throughout its former Empire. Meticulous attention to detail and doing things by the book serve today's historians and researchers well. The most surprising aspect, however, is that the service is free to use both the online service or if you're one of the 90,000 annual visitors to Kew. How long it can survive as a free service in these hard-pressed times remains to be seen. I'm sure George Osborne has had something to say about that over the past year.

In the meantime, as you tune in to WDYTYA in the coming weeks and watch a tearful celebrity unearth a quirky family store, spare a thought for the National Archives. The dedication of its plucky band of researchers, archivists and conservators along with the nationwide network of county libraries and archives are, for me, the real stars of the show.