I disagree with nhchris’s response of
> It is their inheritance, their birthright, the fruit of their ancestors' labors.
Because there is no natural law that something is “your” inheritance, birthright, or that you have claim to the fruit of your ancestors’ labor. Might makes right is how nature works, and it just so happens that you were born in a time and place where certain “rights” are being upheld, and there is not a stronger party that wants and is able to take them from you.
You can even go further and replace place X and Y with parents X and Y.