See ESC right:

Marriage

Relevant ICESCR Articles:

10(1): The widest possible protection and assistance should be accorded to the family, which is the natural and fundamental group unit of society, particularly for its establishment and while it is responsible for the care and education of dependent children. Marriage must be entered into with the free consent of the intending spouses.

Related Documents:

Convention on the Elimination of All Forms of Discrimination Against Women

European Convention on Human Rights, Protocol No. 7