By the terms of the Statute of Westminster 1931 , each of the Commonwealth realms has the same person as monarch and , to maintain that arrangement , they have agreed to continue the same line of succession ; some realms do so through domestic succession laws , while others stipulate whoever is monarch of the United Kingdom will also be monarch of that realm . In February 1952 , on her accession , Elizabeth II was proclaimed as sovereign separately throughout her realms . In October 2011 , the heads of government of all 16 realms agreed unanimously at a meeting held in Perth , Australia , to proposed changes to the royal succession laws that would see the order of succession for people born after 28 October 2011 governed by absolute primogeniture — wherein succession passes to an individual 's children according to birth order , regardless of sex — instead of male-preference primogeniture . They also agreed to lift a ban on those who marry Roman Catholics . The ban on Catholics themselves was retained to ensure that the monarch would be in communion with the Church of England . The changes came into effect across the Commonwealth realms on 26 March 2015 , after legislation was made according to each realm 's constitution
meeting
Commonwealth Heads of Government Meeting 2011
Succession to the British throne