Just as in Great Britain the King was restrained by Parliament, the Governor had no power to force laws or taxes on a colony without the consent of its assembly.
Lord Mansfield recognised that the 4½% duty was fair and equitable, even desirable to avoid distorting trade between the Windward Islands.
Through the inattention of the king's servants in inverting the order in which the instruments should have passed and been notoriously published, the last act is contradictory to and a violation of the first, and is, therefore, void.Campbell v. Hall has been cited or referred to in several later cases in the British Empire.
Most pointedly it was cited with approval in West Rand Central Gold Mining Company, Limited v. The King,[1] a case which concerned the conquest of the Transvaal and the consequential extinction of the vanquished state's obligations.
Its principles were also discussed and distinguished with respect to colonies acquired otherwise than by conquest, by the Judicial Committee of the Privy Council in its 1938 ruling in Sammut v.
[2] It was also argued in 2008 in R (Bancoult) v Secretary of State For Foreign and Commonwealth Affairs (also known as the Chagos Islanders case), where Lord Hoffmann, in introducing his opinion, stated: Authority for these propositions will be found in Lord Mansfield’s judgment in Campbell v Hall (1774) 1 Cowp 204 (“no question was ever started before, but that the King has a right to a legislative authority over a conquered country.”) This appeal requires your Lordships to determine the limits of that power.
[3]He resumed later: Although the passage from the judgment of Lord Mansfield has regularly been cited for the proposition that the King cannot legislate contrary to fundamental principles of that kind, I suspect that this is to read too much into his remark.
Parliament subsequently passed the Colonial Laws Validity Act 1865 to deal with conflicting jurisprudence that arose in the years following Campbell.