It can be very tempting to use other people’s work when you find common family branches that takes you a generation or more back in time. The Internet has made this very easy through services like private family sites, MyHeritage and Geni, but will you do yourself a disservice?
One of the first things you should look for in other people’s work before using it in your own is whether it refers to a source. And if that is the case, which source does it refer to? There have been many instances of family trees being established based on oral traditions in the family, just to be refuted when someone bothered to look for written sources.
The work you are looking at and want to copy can itself have been uncritically copied from numerous work by other people. If you look closely at years and dates, do they seem likely? Could anyone be 105 years old when they became parents or 5 years old for that matter?
3. Empty generations
In the search for the famous ancestor, some choose to skip a generation that cannot be documented. “It has to be the grandfather who was born 70 years earlier, he has the same surname”. It is easy to think like this when one looks a few hundred years back in time. You should however take it with an extra large pinch of salt or possibly discard it completely when you find information of such undocumented generations in your family tree.
4. Place of birth vs. year of birth
Although our ancestors often could move surprisingly far around the country (and abroad), the distances must have been manageable in reality. If you, in a census, find a mother at one place and then one of her children suddenly is born at the opposite end of the country two days later, the alarm bells should start ringing again.
There are, in fact, fake noblemen out there who are just made up by those who have had the need to do that. For example, the “Norwegian Bratt Family” with 24 kings on the chart has been used and copied on by many hobby genealogists in central Norway despite the fact that the family has been labeled as fabricated for the last 30 years!
We must emphasize that this fake Bratt Family is from Gudbrandsdalen and has nothing to do with the real Bratt family in Trondheim. That family is originally Swedish and is allegedly of royal lineage.