At the birth of a son to James ll, the English lost patience
with their ruler. They were willing to wait for James to die,
but now another Roman Catholic king would follow him.
This was too much for Protestant England to bear;
hence the negotiations with William and Mary began.
During this time of unrest a new nursery rhyme appeared.
"Hush-a-bye Baby" was actually a political poem directed against
James ll and his newborn baby. The "treetop" referred
to the dangerous position of the baby. The "wind"
was blowing from Europe, bringing William and Mary to
England. When the "bough broke," poor King James ll and his
family would tumble from their high political position.
Just before William and Mary arrived, everyone was
singing this seemingly harmless song as an act of
defiance against the hated king.
-from Streams of Civilization