The evolution of the Commonwealth realms has led to the scenario wherein the Crown has both a separate and a shared character; it is a singular institution with one sovereign, but also simultaneously operates separately within the jurisdiction of each country, with the Queen in right of a particular realm being a distinct legal person who acts only on the advice of the Cabinet of that state. This means that in different contexts the term Crown may refer to the extra-national institution shared amongst all 16 countries, or to the Crown in each realm considered separately. However, though the monarchy is therefore no longer an exclusively British institution, for reasons historical, of convenience, or political it may in the media and legal fields often still be elaborated as the British Crown, regardless of the different, specific, and official national titles and terms that exist in each jurisdiction; for example, in Barbados the Queen is titled as Elizabeth II, Queen of Barbados, or simply the Queen of Barbados. To guarantee the continuity of this arrangement, the preamble of the 1931 Statute of Westminster stipulates that any alteration to the line of succession in any one country must be voluntarily approved by the parliaments of all the realms, or, alternately, a realm may choose to end its participation in the shared monarchy.
From a cultural standpoint, the shared nature of the Crown is less clear. In all realms, the sovereign's name and image and other royal symbols are visible in the emblems and insignia of governmental institutions and militia. The Queen's effigy, for example, appears on coins and banknotes in some countries, and an oath of allegiance to the Queen is usually required from politicians, judges, and new citizens. It is argued, however, that the Crown throughout the realms remains essentially British and primarily of the United Kingdom, despite the legal and cultural evolution of the Commonwealth since the 1930s, whereas others emphasise the Crown as a shared link between the Commonwealth realms, with the Crown in right of their own nation having unique domestic characteristics.