Only one of the 13 passed on the surname, or we almost died out

In the past, it sometimes happened that only one son passed on his father's surname (and the genes of his father and mother), even though his father had fathered many children. This situation arose because some of the father's children were daughters, some sons did not live to reproductive age, and of those who did, only some married and had children. This could lead to a situation where only one in ten descendants passed on the surname.

In the family of Václav Vachuška and Johanna, born Poleníková, from Dobrotice, only one of their 13 children passed it on! The fate of their five sons was as follows:

1) Matěj (1787–): nothing is known about his life; he probably did not pass on his surname,

2) Josef (1789–1790) lived to be one year old and was unable to pass on his surname,

3) Jan Křtitel (1791–1838) lived to the age of 47 as a bachelor and most likely did not pass on his surname,

4) Václav (1801–1856) lived to be 54 years old, during which he fathered at least five children with Johanna, born Rybáková, at least two of whom passed on the surname,

5) František Xaverius (1803–1809) lived to be five years old and was unable to pass on his surname.

Therefore, it can only be said with certainty that Václav passed on his surname.

The chance that father Václav would pass on his surname through (this) son Václav was even lower because Václav was born as the tenth child! If Václav's father had decided after the birth of his ninth child that he did not want any more children, or if he had died, or if his wife had died and he had not remarried, or if he or his wife had become infertile, then Václav would not have been born and his five grandchildren, 17 great-grandchildren, 22 great-great-grandchildren... and all his descendants living today!

Václav's son Jan of Slatina has a similar story. Although Jan had eight children with his wife Anežka, born Rodinová, only two of his sons could pass on the surname, and of these two, only one can be said with certainty. The fate of Jan's sons was as follows:

1) Jan Nep. (1862–): nothing is known about his life; he probably did not pass on his surname,

2) Václav (1867–) he lived to a ripe old age and had at least seven children with Anna, born Vaněčková, four of whom were sons who could theoretically pass on the surname,

3) Josef (1870–1872) lived to be one year old, he could not pass on his surname,

4) František (1872–1874) lived to be one year old, he could not pass on his surname.

Upon closer examination, this situation, where only one descendant passes on the surname, is not so unusual...

Jan Vachuška (1734–1807) and his wife Kateřina ze Sedla fathered eight children in total, and the following information about their sons can be found in the parish registers:

1) František (1771–): nothing is known about his life; he probably did not pass on his surname,

2) Jan (1778–): Nothing is known about his life; he probably did not pass on his surname,

3) Jakub (probably 1780 or 1782–1842) lived to a ripe old age and had 11 children with Marie Magdalena, born Jandová, of whom only two are known to have passed on the family name...

One of Jakub's two sons, Tomáš, had nine children with his wife Kateřina Haufová, born Harašková, and only one son can be said with certainty to have passed on the surname...

It is therefore clear from the records that in the past, the surname Vachuška was passed on to subsequent generations in several cases by only one descendant out of many.

And how many sons and from how large a family passed on the surname to you?