Here's another one, written by Vic Gammon and lifted from Digital Tradition by me.

Kings and Queens of England

Now Charles II had eleven bastard children
And George III went mad
And Edward VII they thought was Jack the Ripper
But Richard III weren't as bad as Shakespeare thought he was
Victoria lay back and thought of England
Charles I lost his head
Well the best thing about those Kings and Queens of England
Is that most of them are dead.

Singing
Rule Britannia
Britannia waives the rules
Kings, Queens, Jacks and Knaves and tyrants
Cheats and fools.

Now William III was a protestant and Dutchman
And James I was a Scot
And George I spoke nothing else but German
What a mixed-up, inter-bred lot.
And William I was a grasping Norman bastard
Believe me, it's no lie.
Well there hasn't been an English king of England
Since Harold got one in the eye.

Chorus

Now she was a well-heeled blue-blood Cinderella,
Him Prince Charming with big ears,
But he has a thing going with the ugly sister
So it ended all in tears.
So arise now ye ghosts of old Oliver Cromwell,
Brave Harrison and Tom Paine.
Won't you rid our land of this monstrous carbuncle
And bring sunshine after the reign.

Chorus

Note: "Monstrous carbuncle" was Prince Charles' infamous description of some piece of modern architecture (design for the Tate Gallery extension??)