My Irish Grandmother's version was:

My uncle Mick, he had a stick
He made one hell of slaughter
He killed ten thousand Orangemen
at the Battle of the Boyne Water.
One flew up and one flew down and
one flew round the corner
poor John Bull got go a bullet up him bum
and (can't remember the last line)

My English father later told me about the battle of the Boyne.
The rhyme was a lot of nonsense