Particularly since Elisabeth I came long after that date. It’s definitely not 1414.

I'd say it's 1688: https://en.wikipedia.org/wiki/Glorious_Revolution

Other possible choices are 1708 (last example of the monarch refusing royal consent to an act of parliament, Queen Anne on the Scottish Militia Bill), or 1834 (last example of the monarch dismissing their government, William IV sacking the Whigs; he had to have them back in 1835 as the Tories he installed couldn't command a majority of the Commons).

Or you can point to things like the Kerr Sacking (in Australia, but using (vice-)regal power) and say it's not quite done yet, though in decline for centuries...

I often wonder if George was merely the figurehead for colonial frustrations. After all, Parliament precipitated the revolution by insisting that they had the power to tax the colonies.

It is hard to put an exact date on it - but 1414 is the first time the King acquiesced that parliament had to give approval for new laws.