If your family have never left Devon, if you have access to all the relevant records, if you have the energy to do the research and  a few oral memories from older members of your family - if this is your scenario, then creating your family history for generation after generation is straightforward and just a matter of having the time to do it.

The story of the research into the Leleux family, into which Jessie Stentiford married, illustrates quite another set of circumstances. John Humphrey and Bruce Humphrey are brothers who live and work on opposite sides of the world. Working independently, they, and other members of this family, have devoted years to the task but even now, with all the resources available to  21st century family historians, cannot discover key facts  about people who lived and died in the last 100 years, let alone further back in time.

So how can this happen? Inhabitants of the British Isles are surrounded by myriads of vast archives of diverse records covering anything from 15th century laundry lists to 20th century hospital records - surely there will be a clue somewhere? And yes, in the UK there's a good chance there will be. But once an ancestor leaves these shores, it can be very different. There may have been no intention to hide one's identity - it's simply that record-keeping varies so much across the world.

But some people did want to hide their true identity. Divorce was so difficult until fairly recent times that desertion was more common than we might suppose. Precisely because UK records were so thorough, many thought it better to go abroad to avoid being traced and, at the same time, to change surnames. One of the problems faced by the Leleux descendents is a Catholic marriage just a few generations back. Officially, that was for life for both parties - unofficially, the couple themselves may have had to make the best of quite a different outcome.

And we come now to the question of fabrication. In the tight little world of a Devon village, watched over by an eagle-eyed vicar who missed nothing, subterfuge was impossible. In a large city like London, the situation was completely different - who was to contradict  anything you chose to say? Civil Registration did not become compulsory until the mid -1870s and many years passed after this time without enforcement of the law.