The decline in allegiance to the monarch as the common ground for membership of the Commonwealth of Nations led to the Charter of the Commonwealth 2013, expressing common values and aspirations shared by member nations. This Charter grew out of the report of the Eminent Persons Group (EPG) established in 2011. The author was a member of the EPG and played a role, that is described, in drafting the Charter. The article explains the emergence of the Charter; its antecedents; the approval of the concept at the Perth CHOGM 2011; the compromises that marked its adoption; the limited influence of the Charter illustrated by the continued operation of criminal laws against LGBTIQ Commonwealth citizens; and other recent developments that suggest a possible future value for the document. The deletion of an enforcement mechanism proposed by the EPG is identified as a major practical weakness of the Charter. The author suggests that if it is impossible to define and enforce such a Charter, the long–term future of the Commonwealth, as an influential post–imperial invention, must be in doubt.