[dragonwriter]

> The question of "Who has power in the British Empire" was settled pretty definitively back in 1649, when Charles I lost his head.

> If you want to split hairs, we can say that it was settled more definitively in 1661, when Cromwell's head was put on a spike outside Westminster hall.

Those are both wrong. It was settled in 1911 when George V made clear he would intervene by appointing new life peers if necessary to assure passage of reforms which would strip the House of Lords of its power to reject legislation, which finally settled that the Commons would henceforth be effectively the sole decisive ruling body of the Empire.

Prior to that, the Commons (democratic, approximately) and Lords (decidedly not) had an ebb and flow of power, with the Lord's sometimes being more powerful and the Commons sometimes being more powerful (including, for a period, the Commons abolishing the Lords with Cromwell's support, but that, like Cromwell, didn't last.)