(at 224): “Allegiance” examines the relationship between an individual and a sovereign power from the point of view of the individual, and principally by reference to duties and obligations which the individual may owe to that sovereign power. In a monarchy, questions of allegiance may be personified and, if that is done, insufficient attention may be given to identifying the distinction between relevant separate sovereign powers. The notion of personal allegiance “lay at the very root of the feudal system” but long before federation that state of affairs had ceased to exist. In 1886, Lord Coleridge CJ had explained that allegiance was due from subjects to the Crown in “the politic” not the “personal capacity” of the sovereign. In Sue v Hill  HCA 30, Gleeson CJ, Gummow and Hayne JJ discussed this and other senses in which the term “the Crown” has been used in constitutional theory derived from the United Kingdom.”
(at 226-229): “The notion that an individual became a British subject at birth anywhere within the dominions of the Imperial Crown and by reason of allegiance to the Imperial Crown, had been abandoned both in the United Kingdom and in Australia before the birth of the prosecutor. The post-war legislation in both countries, the 1948 UK Act and the Citizenship Act, recognised that the metaphysical indivisibility of the Imperial Crown no longer made constitutional or political sense. Notions of allegiance as the factum upon which nationality laws and status turned were accommodated to international realities consequent upon the disappearance of the British Empire. Those realities were reflected in the Royal Style and Titles Act 1953 (Cth). This recited an agreement reached at a meeting of British Commonwealth Prime Ministers in London in December 1952 that “the Style and Titles at present appertaining to the Crown are not in accord with current constitutional relationships within the British Commonwealth”.
Section 4 of the statute stated the assent of the Parliament to the adoption by Her Majesty, for use in relation to the Commonwealth of Australia and its Territories, of the Royal Style and Titles: “… of the United Kingdom, Australia and Her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith”. Thereafter, and even before the removal, by the Royal Style and Titles Act 1973 (Cth), of the specific reference to the sovereignty of the United Kingdom, it was plain that in so far as notions of allegiance were concerned the sovereign had several and distinct politic capacities. The 1953 statute, as the preamble indicated, was an exercise of the legislative power with respect to external affairs.
There remained nothing in notions of allegiance to the Crown in the one Imperial politic capacity. That in turn had several consequences. First, it emphasised the point later made in Sue v Hill that, whilst the references in covering cl 2, the Schedule, and other provisions of the Constitution, to the sovereign identify that person for the time being occupying the hereditary office of sovereign of the United Kingdom, the legislative and executive powers and functions entrusted by Ch I and Ch II of the Constitution to the sovereign are enjoyed in respect of the Australian body politic.
It may be accepted that, at the time of federation, the state of subjection identified in s 117 was to the indivisible Imperial Crown. But, as a result of the changes made in the constitutional relationships within the British Commonwealth which were reflected in the various statutory provisions that were made between 1948 and 1953 and are mentioned earlier, the allegiance owed by the subjects spoken of in s 117 was to the Crown in its Australian politic capacity. There no longer was in constitutional theory or political reality the Imperial Crown of earlier days. To continue to read s 117 as it had been read initially would have been to deprive it of any useful operation.”