Under the concept of “precedency by proximity of the degree of relationship”, the closest relative to the deceased within the same line of successors excludes more distant relatives from the succession.
There are three lines of successors:
the direct line, which includes the deceased’s children and their descendants (the deceased’s grandchildren) as well as his parents;
the privileged collateral line, which includes the deceased’s brothers and sisters and their descendants (the deceased’s nieces and nephews) in the first degree;
the ordinary collateral line, which includes the other descendants of the deceased's brothers and sisters.
Privileged collateral line
In order for the deceased’s brothers and sisters to have an equal share in the succession, they must have the same parents as the deceased (i.e. they must be “whole-blood” relatives). The same applies to their own descendants: in other words, to have an equal share of the succession, the deceased’s nieces and nephews must issue from the same parents.
Different rules apply to half-brothers and half-sisters.
If there are only sisters and brothers in the privileged collateral line, the succession is partitioned into two equal shares, one for the deceased’s paternal line and the other for the maternal line. Each share is then divided by the number of heirs (brothers and sisters) within each line.
Ralph dies without having made a will. He is married to Pauline and has no children.
He has three brothers, all still alive:
Louis and Roger, who have the same parents as Ralph (i.e. they are Ralph’s whole-blood brothers);
Pierre, who has the same mother but a different father (the mother’s second spouse). He is therefore Ralph’s uterine brother.
Sharing the succession
Ralph’s succession is worth $45,000 (after partition of the family patrimony and liquidation of the matrimonial regime, since Ralph was married to Pauline).
Pauline receives two-thirds of the succession, i.e. $30,000. The other one-third, or $15,000, is then divided equally between the paternal line ($7,500) and the maternal line ($7,500).
There are two brothers in the paternal line, Louis and Roger, and they each receive one-half of the portion passing to that line, or $3,750.
There are three brothers in the maternal line, Louis, Roger and Peter, and they each receive one-third of the portion passing to that line, or $2,500.
Since Louis and Roger are whole-blood brothers, they receive shares from both parental lines (for a total of $6,250 each). Peter, as a uterine brother, only receives a share from the maternal line ($2,500).