Lir was a great Irish King and the Lord of the Sea. King Lir married his love Aobh and they had four beautiful children together: Fionnuala, Aodh, Fiachra and Conn. Much to Lirs despair his wife Aobh passed away. Heartbroken and lonely Lir eventually remarried Aobhs sister Aoife. It wasn't long before Aoife became jealous of her husbands affection for his children. She plotted to get rid of them so that Lir would turn his affection to her.
Aoife took the children to Lake Derravaragh - the Lake of the Oaks, and cast a spell on them. She turned them into four swans destined to spend 300 years on Lake Derravaragh, 300 years on the Sea of Moyle and 300 years on Inis Glora. The spell would not be broken until the sound of Christian bells set them free. After she realized what she had done she felt remorseful so she allowed them to keep their human voices so that they could sing.
When Aoife told their father that they had drowned in the lake he ran straight to the lake only to find four of the most beautiful swans he had ever seen. He could hear their voices but they were nowhere to be seen. To his horror he realized that the swans were his beloved children, and when they had told him what their wicked stepmother had done he had flew into an almighty rage. He transformed Aoife into an air demon for eternity.
Lir visited his children everyday until he passed away leaving the swans broken hearted. The swans spent the next 900 years singing their sad and beautiful songs which moved anyone who heard. When the spell lifted the once beautiful swans found themselves old and frail and close to deaths door. Their final request was that they were to baptized and died shortly after, becoming reunited with their beloved parents in heaven.