Number of Ancestors

In a previous entry we have discussed the correct way to name our more distant ancestors on each generation. We will complete that entry adding the theoretical number of ancestors for each generation.  Genealogist call this chart a “Chronologic-Genealogic” Table.

We talk about theoretical number of ancestors because we know the marriage between relatives reduces dramatically the number of ancestors. The happily reigning Juan Carlos I is an extreme example of this situation, as on this 8^th generation (128 ancestors) he descends 22 times from King Charles III, 22 times from his brother Philip (Duke of Parma) and finally 22 times from Philip’s wife that was also a Bourbon, daughter of Luis XV, King of France. More than half of King Juan Carlos I on that generation descends from the same Bourbon ancestor. Of course this is an extreme example, but in rural Spain marriages usually happened in the same village; therefore marriages between relatives (even first of second cousins) were very common.

Generation	Estimated Year	Ancestor	Number of Ancestors
1	2000	Self	1
2	1970	Parents	2
3	1940	Grandparents	4
4	1910	Great Grandparents	8
5	1880	2nd Great Grandparents	16
6	1850	3rd  Great Grandparents	32
7	1820	4th Great Grandparents	64
8	1790	5th Great Grandparents	128
9	1760	6th Great Grandparents	256
10	1730	7th Great Grandparents	512
11	1700	8th Great Grandparents	1,024
12	1670	9th Great Grandparents	2,048
13	1640	10th Great Grandparents	4,096
14	1610	11th Great Grandparents	8,192
15	1580	12th Great Grandparents	16,384
16	1550	13th Great Grandparents	32,768
17	1520	14th Great Grandparents	65,536
18	1490	15th Great Grandparents	131,072
19	1460	16th Great Grandparents	262,144
20	1430	17th Great Grandparents	524,288
21	1400	18th Great Grandparents	1,048,576
22	1370	19th Great Grandparents	2,097,152
23	1340	20th Great Grandparents	4,194,304
24	1310	21st Great Grandparents	8,388,608
25	1280	22nd Great Grandparents	16,777,216

http://www.hispanicancestors.com