Long ago, there was a king in Ireland called Lir. He had four
beautiful children: a son, a daughter and twin sons. Their mother
died and King Lir wanted them to have a new mother. So it came
to pass that he married his wife's sister, Aoife. Soon after, Aoife
became jealous of the King's children because she saw their
great happiness with the King. So she decided to get rid
of the children.
One beautiful summer day, she took the children out to a lake
for a swim. As soon as the children went into the water, she cast
a spell on them, turning them into swans. However, Aoife's spell
didn't take away the children's human voices and they were set
free 900 years later when St. Patrick came to Ireland. The swans
became humans again, but they were old and died instantly.