Salic Primogeniture is a Law of Succession. It is different from Semi-salic Primogeniture in that females cannot trace inheritance. This means that only male lines can inherit. For example, your brother can inherit but your grandsons through your daughter cannot.
Primogeniture means that the oldest candidate inherits, in this case the oldest son. All male heirs through male lines of the oldest son rank above the second oldest son in the line of inheritance.
As as example: King John has three children: William, Edith and Robert. William has two children, Constance and John. Edith is married and has a son Guy. Robert has a son Roger. Let's illustrate this in a chart:
King John | |--------------|------| | | | William Edith Robert | | | |--------| | | | | | | Constance John Guy Roger
Following the law of salic primogeniture, the line of inheritance is as follows:
- John the younger