Why do the majority of royal houses use the maternal line for descendancy as opp

Question: Why do the majority of royal houses use the maternal line for descendancy as oppose to the paternal line!?
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Because the maternal line is keeping the One Blood Line, the parental line includes many other Blood LinesWww@QuestionHome@Com

Says who!? The Royal family in the United Kingdom practices cognatic primogeniture, along with Denmark, Monaco, and Spain--a practice that allows the female to succeed only if she has no living brothers and no deceased brothers who have left living descendants!.

Uterine primogeniture, which is otherwise known as tanistry, is (or rather was) the succession of a male ruler through a female ancestor or spouse!. Usually a council or parliament choose such a king from a field of closely related candidates based upon his ability to lead!. Tanistry has only been practiced by the Picts of Scotland (Macbeth being the last example of this) and the Etruscans!.Www@QuestionHome@Com

I don't know that the "majority" do that, at all!.
England may be one example!.!.but the only reason that it happened was because Dad (was King) had no sons!. And, Dad himself was 2nd in line, when his brother abdicated!.
You may know of other lines, but you would have to go back in the lineage to be sure of your point!.Www@QuestionHome@Com

the romans valued the father in their society and thats where the originalities of western civilizations come from!. if you want to, look up paterfamilias!.Www@QuestionHome@Com

they dont
they all use paternalWww@QuestionHome@Com