Another Welsh Goddess, whose name means "Silver Wheel" or "Silver Circle". Like Blodeuwedd, Arianrhod is part of the Welsh Triple Goddess, as the mother aspect. She ruled over the stars, the moon and the sky, and she lived in an astral palace called Caer Arianrhod (also known as the constellation Corona Borealis). This palace was the destination of the souls of the dead, between incarnations. She lived there with her husband, Nwyvre, who is known today by name only.
She was the daughter of Don (who was the Welsh version of the Goddess Danu, though Don was sometimes depicted as a God as well as a Goddess).
Arianrhod had 2 sons, Llew Llaw Gyffes and Dylan. The myth of their birth states that she became pregnant (and immediately gave birth) during a virginity test where she stepped over the staff of her brother, Gwydion. The implication is that her sons were born from either rape or an incestuous affair.
As a result, she banished Dylan to the sea and cursed Llew with 3 curses. One of those was that he would never take a human wife. That led to the story of Blodeuwedd, told above. Her brother Gwydion raised Llew and together they tricked Arianrhod into releasing him from the other 2 curses as well
Though these myths don't reflect her attributes, she is associated with cosmic time and tides, fate, life and death, fertility and the power of the moon.