Bonfire night

To which noted leader does this clause from a National Review article by John Derbyshire refer?

and his court degenerated at last into a whispering, bickering nest of favorites.

Does your previous guess become more or less plausible if we add the information that:

He was foul-mouthed, had a speech impediment, and was physically unattractive.

or that he once said

"I am surprised that my ancestors should have allowed such an institution to come into existence."

Yes, it's James I.