Chances are the amount of years making a generation has more than doubled in the past few thousand years.
Right now at the low end we have 20 and at the high end 30. Of course, what makes a generation varies from country to country and region to region.
During the year 1100, the European population was around 61 million, and by 1500, the population was around 90 million.
If we use today’s high end of 30 years for one generation, we will have around 30 generations leading back to the year 1,100.
I give you a hint:
More than 1 Billion individuals…