deny (someone's) birthright

Translations
лишить (чьего-либо) законного права
He felt that his siblings were trying to deny his birthright.
Он чувствовал, что его братья и сестры пытаются лишить его законного права.
Definitions
To refuse or withhold from someone the rights, privileges, or inheritance that they are entitled to by birth, often referring to something fundamental or deserved, such as citizenship, property, or social status.