I'm not sure how to phrase this question clearly. I guess for simplicity let's pretend power is some sort of thing that can be transmitted from person to person. Do kings and queens of England/UK have power because of their links to their ancestors? Or do they have it in their own right? For example, does Elizabeth II's legitimacy still derive from her heredity, or is it somehow a part of her now? I guess I'm wondering where the root of power is for the British: with the current monarch, or with the beginning of the dynasty?
I assume the answer will vary depending on the time period.
Thanks!
The reigning dynasty holds its title due to the Act of Settlement 1701 by which Parliament conferred the crown on Sophia, Electress of Hanover and her Protestant descendants. Sophia was a granddaughter of James I of England, leading Burke to later say that the ruling dynasty held their title by "hereditary descent qualified with Protestantism". So Elizabeth II holds her title by hereditary right as established by the law of the land.
If you're interested in reading about the debate on whether the post-1688 monarchy held its title to divine right or by the choice of the people, I recommend J. P. Kenyon's Revolution Principles: The Principles of Party 1689-1720 (Cambridge: Cambridge University Press, 1977).