This fundamental principle, with these qualifications or explanations of it, was clearly, though quaintly, stated in the leading case known as „Calvin‟s Case,‟ or the „Case of the Postnati,‟ decided in 1608, after a hearing in the exchequer chamber before the lord chancellor and all the judges of England, and reported by Lord Coke and by Lord Ellesmere. Calvin's Case, 7 Coke, 1, 4b-6a, 18a, 18b; Ellesmere, Postnati, 62-64; s. c. 2 How. St. Tr. 559, 607, 613-617, 639, 640, 659, 679. The English authorities ever since are to the like effect. Co. Litt. 8a, 128b; Lord Hale, in Harg. Law Tracts, 210, and in 1 Hale, P. C. 61, 62; 1 Bl. Comm. 366, 369, 370, 374; 4 Bl. Comm. 74, 92; Lord Kenyon, in Doe v. Jones, 4 Term R. 300, 308; Cockb. Nat. 7; Dicey, Confl. Laws, pp. 173-177, 741.
The fundamental principle of the common law with regard to English nationality was birth within the allegiance-also called „ligealty,‟ „obedience,‟ „faith,‟ or „power‟-of the king. The principle embraced all persons born within the king‟s allegiance, and subject to his protection. Such allegiance and protection were mutual,-as expressed in the maxim, „Protectio trahit subjectionem, et subjectio protectionem,‟-and were not restricted to natural-born subjects and naturalized subjects, or to those who had taken an oath of allegiance; but were predicable of aliens in amity, so long as they were within the kingdom. [highlight]Children, born in England, of such aliens, were therefore natural-born subjects.[/highlight] But the children, born within the realm, of foreign ambassadors, or the children of alien enemies, born during and within their hostile occupation of part of the king‟s dominions, were not natural-born subjects, because not born within the allegiance, the obedience, or the power, or, as would be said at this day, within the jurisdiction, of the king.
The English authorities ever since are to the like effect. Co. Litt. 8a, 128b; Lord Hale, in Harg. Law Tracts, 210, and in 1 Hale, P. C. 61, 62; 1 Bl. Comm. 366, 369, 370, 374; 4 Bl. Comm. 74, 92; Lord Kenyon, in Doe v. Jones, 4 Term R. 300, 308; Cockb. Nat. 7; Dicey, Confl. Laws, pp. 173-177, 741.
Lord Chief Justice Cockburn . . . said: „[highlight]By the common law of England, every person born within the dominions of the crown, no matter whether of English or of foreign parents, and, in the latter case, whether the parents were settled, or merely temporarily sojourning, in the country, was an English subject,[/highlight] save only the children of foreign ambassadors (who were excepted because their fathers carried their own nationality with them), or a child born to a foreigner during the hostile occupation of any part of the territories of England. No effect appears to have been given to descent as a source of nationality.‟ Cockb. Nat. 7.
IANAL but I'm liking the language of this opinion.
I like, much like in the Berg v Obama opinion that the Court exercises its discretion and addressed additional issues.