Is A.A. Milne’s "King John’s Christmas" about Bad King John?

Aside from the name and some unpopularity (really, King John wasn’t that bad), I don’t recognize anything particular to the man.

According to this, yes.

King John of England WAS the inspiration for this poem.

While we’re on the subject – anyone know what the name of this particular rhyme-scheme is?

King John was not a good man –
He had his little ways.
And sometimes no one spoke to him
For days and days and days.
And men who came across him,
When walking in the town,
Gave him a supercilious stare,
Or passed with noses in the air –
And bad King John stood dumbly there,
Blushing beneath his crown.

ABAB
ABBBA