Re the Stepney Election Petition; Isaacson v Durant  17 QBD 54 was a landmark decision of the Kings Bench Division of His Majesty’s High Court of Justice in England, which established the rule throughout the British Empire that a natural born subject becomes an alien when the sovereign ceases to have dominion over the territory in which the person resides. Contrary to the long-standing principle set in the 1600’s Calvin case, Lord Coleridge CJ said (at 65-66): “…as the statutes referred to the Crown and not the sovereign, allegiance was due to the King in his politic, and not in his personal, capacity.” It’s rather fascinating to read Lord Coleridge discuss the principle of the divisibility of the Crown way back in 1886.
The decision had far-reaching immediate implications. Only a decade later in the United States, (US v Wong Kim Ark (1898) 169 US 649), Gray J. referred to what was then recent English authority in which it was said that: “feudalism being long gone, it was to the sovereign in his or her politic not personal capacity that allegiance was due.”
This recognition of individual Crowns greatly assisted the gradual emergence of Australia as an independent, sovereign nation, and the development of the Commonwealth as an association of independent nations. It led to the creation of individual national citizenships as opposed to the term “British subject” being loosely applied throughout all the colonies and dominions, from the British Nationality Act 1914 came the British Nationality Act 1948 (UK) and our Nationality and Citizenship Act 1948 (Cth). The concept of “an indivisible Imperial Crown” had given way to the recognition of the principle of the divisibility of the Crown, and the consequential acceptance that the phrase “subject of the Queen” no longer merely means “subject of the Queen of the United Kingdom” but rather, in relation to Australia: “subject of the Queen of Australia”.
It is referred to countless times in Australian courts, regarding the established common law principle that, (as explained recently in Flowers v State of New South Wales (No 5)  NSWSC 887 (from 111): “…allegiance is to the body politic, being the State as an entity, not the government and not the monarch personally.” Because of this decision, for the last 136 years it has been a principle of statutory interpretation throughout all the colonies and dominions of the former British Empire that references to the Crown in legislation are generally references to the particular body politic of the particular state or nation, and not to the Queen in a personal sense. As recently stated in Love v Commonwealth  HCA 3 (at 107-108): “By federation, the Crown to which such allegiance was owed was understood to be the monarch “in his politic, and not in his personal capacity” and the full feudal dimensions of what might once have been meant by the “protection” of the Crown had been lost in the mists of time.”
The concept of the Crown as a corporate entity was well understood by Federation. As observed in Sue v Hill  HCA 30 (from 83) the drafters knew the term “…was used in several metaphorical senses.” Lord Penzance had said in 1876, “We all know, that the Crown is an abstraction.” Maitland, Harrison Moore, Inglis Clark and Pitt Cobbett, amongst many distinguished constitutional lawyers, took up the point. In 1901, Frederic Maitland published his book “The Crown as Corporation“.
This decision has been regularly referred to by the High Court to explain the concept of allegiance, as allegiance itself is what provides the distinction between a “subject” and a “non-subject” or “alien”. The distinction between having allegiance to Her Majesty in the context of another body politic, (Crown of India, Crown of the United Kingdom, etc) and having allegiance to Her Majesty in the context of the Australian body politic, was noted in reference to this principle in Pochi v MacPhee  HCA 60; and directly referred to in such prominent cases as Nolan v Minister for Immigration and Ethnic Affairs  HCA 45, Sue v Hill  HCA 30, Re Patterson; ex parte Taylor  HCA 51, Shaw v Minister for Immigration and Multicultural Affairs  HCA 72, Singh v Commonwealth of Australia  HCA 43, and many more, as recent as Chetcuti v Commonwealth of Australia  HCA 25.
This is not a distinction limited to Australia as a body politic. Each state Crown is a separate legal entity/body politic to the next state Crown, just as the Commonwealth Crown is a separate legal entity/body politic to the UK Crown or other nations Crowns. In Sue v Hill  HCA 30, (at 165), Gaudron J stated that it is “…implicit in the existence of the States as separate bodies politic with separate legal personality, distinct from the body politic of the Commonwealth with its own legal personality. The separate existence and the separate legal identity of the several States and of the Commonwealth is recognised throughout the Constitution, particularly in Ch III.”
I am currently a part of Her Majesty’s body politic of the State of New South Wales, and the lawmaking authority of this body politic is the New South Wales Parliament. It is a state within a federation, so I am also a part of Her Majesty’s body politic of Australia, and the lawmaking authority of that body politic is the Commonwealth Parliament. From their passage of the Royal Style and Titles Act 1973 onwards, when Her Majesty acts in relation to Australia, she officially acts as Queen of Australia. But this did not apply to the former colonies which became states.
Consistent with the principle described in this decision, prior to 1986 the residents of the Australian states still owed allegiance to the “Queen of the United Kingdom” while the same residents as Australian citizens owed allegiance to the “Queen of Australia”, two very “distinct and separate” legal entities. The “Queen of the United Kingdom” ceased to act in relation to the states with the passage of the Australia Acts 1986, the effect of which, quite arguably created a “new Crown” in each of the states, which would equally be consistent with the principle described in this decision.
Some states have amended their legislation to better reflect this “allegiance to the body politic” interpretation set in this decision. For example, certain legislation governing the state courts and legal practice contain an oath “to the people of the State of…”, rather than “…to the Queen”. See the Acts Amendment and Repeal (Courts and Legal Practice) Act 2003 (WA), and the Courts and Tribunals Legislation (Further Amendment) Act 2000 (Vic) amending section 6(1)(c) of the Legal Practice Act 1996 (Vic). As Wheeler JA rightly observed (at 17-18) in Glew v Shire of Greenough  WASCA 260, (with whom Pullin and Buss JJA agreed) the change in terminology did not effect any change to constitutional reality, and is in fact completely consistent with constitutional reality.
In relation to this decision, on page 386 of “Constitution of New South Wales“, Anne Twomey notes that “As the body politic was a creation of law, then allegiance could be changed by a law-making authority.” referring to the decisions reference in Re Patterson; ex parte Taylor  HCA 51 (at 224), that “the body politic is a creation of law and, as a consequence, the allegiance would be changed by any validly made law or by a lawmaking authority.”