Many families into one family

It is nice to trace your family back as far as you can, but the documentation of the working class gets fewer and less reliable the closer you get to the 16^th century. Once you get pass that if you are lucky you find a few upper-class people like Knights, Lords even some Kings and Queens. Remember your direct descendants double every generation your go back, but the population gets less and less and only the upper classes are documented. So you are related to a whole group or even more lightly many groups of people until even they marge into one group the human family.