The English Bill of Rights?

Question

Which one is the most important to the parliament and why?

1.That the pretended power of suspending the laws or the execution of laws by regal authority without consent of Parliament is illegal
4.That levying money for or to the use of the Crown by pretence of prerogative, without grant of Parliament, for longer time, or in other manner than the same is or shall be granted, is illegal
5. That it is the right of the subjects to petition the king, and all commitments and prosecutions for such petitioning are illegal
9. That the freedom of speech and debates or proceedings in Parliament ought not to be impeached or questioned in any court or place out of Parliament
10. That excessive bail ought not to be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted
13. And that for redress of all grievances, and for the amending, strengthening and preserving of the laws, Parliaments ought to be held frequently

Answer 1

Of that list, 1, 4, 9, and 13 were all very important to parliamentary supremacy in England.

In the short run 4 and 9 were important, but in the long run 13 has proven to be the most important. Changing Parliament from an institution that only met when the Crown needed taxes to an institution that met on a regular basis raised Parliament to a co-equal status with the Crown. When Queen Anne died and King George I succeeded to the throne, that permanent status gave Parliament the ability to play a major role, especially in a monarchy dependent on local advisors (as the king's native tongue was German).