“Succession to the Crown Act”, Acts of the United Kingdom Parliament2013 (20): Section 3(1), (2013), http://www.legislation.gov.uk/ukpga/2013/20/2018年1月26日閲覧, "A person who (when the person marries) is one of the 6 persons next in the line of succession to the Crown must obtain the consent of Her Majesty before marrying."