King Charles’s head

(n.) the object of an obsession; something with which you are fixated

A King Charles’s head is an object of an obsession.

Probably the only thing that most people know about King Charles’ head is that it was removed, fairly forcefully, at his execution in London in 1649. So what does the death of the only executed English monarch in history have to do with a mental fixation?

If you’ve read Dickens’ David Copperfield, you’ll know this one already. Richard Babley, better known in the story as Mr Dick, is the kindly, gentle-natured, yet mentally damaged man who lives with David’s well-meaning aunt, Betsy Trotwood, in her house in Dover. For years, Mr Dick has been working on his “memorial”—some manner of grand speech, eulogizing an unknown figure he greatly admires—but every time he starts to write, thoughts of the execution of Charles I begin to drift into his thoughts and he ends up writing about him instead.

Mr Dick’s obsession, we’re told, stems from the fact that he sees a parallel between his own damaged life and the downfall of King Charles:

“Did he say anything to you about King Charles the First, child?”

“Yes, aunt.”

“Ah!” said my aunt, rubbing her nose as if she were a little vexed. “That’s his allegorical way of expressing it. He connects his illness with great disturbance and agitation, naturally, and that’s the figure, or the simile, or whatever it’s called, which he chooses to use. And why shouldn't he, if he thinks proper?”

Charles Dickens, David Copperfield (1849)

Some commentators have interpreted Mr Dick’s struggle to keep his addled mind clear while working as a reference to Dickens himself, and have even gone so far as to suggest Mr Dick’s troubled life might be the author’s nudge to his own famously troubled childhood. But no matter how Dickens intended the character to be interpreted, it is his obsession with King Charles that lies at the root of the expression above.

Such was the popularity of Dickens’ work that by the 1860s, King Charles’s head was already being used as an expression of obsession or fixation—and in particular one that intrudes on your day to day life, or stops you from working.