Fand is a Celtic sea goddess also known as Queen of the Fairies and wife of Manannán. Manannán mac Lir is a sea deity and referred to as the first ruler of the Manx Nation and very closely linked with the Isle of Man. He is usually associated with the Tuatha Dé Danann. The Tuatha Dé Danann is a race of Celtic people with supernatural abilities. They arrived in Ireland from four cities 'in the north' (thought to be Norway) where they learned their supernatural skills. They are mentioned in 'The Book of Leinster' dating from about 1160 AD which refers to ancient Irish history and legend. On the Isle of Man, Manannán is known as Manannán beg mac y Leir (little Manannan son of the sea). Manannán is the son of Lir, the Celtic god of the sea.
The Ulster Cycle (an Rúraíocht), which is a selection of medieval Irish legends, tells the story of Fand and her love affair with Cú Chulainn. Cú Chulainn features in Manx folklore and is a hero in Irish sagas. Cú Chulainn falls in love with Fand, wife of Manannán. Cú Chulainn's wife, Emer, decides to kill Fand, but when she realises the strength of her love for him decides to give him up to her. Fand is so impressed by this that she decides to leave Cú Chulainn and return to the Isle of Man and her husband Manannán. Manannán had always known that her affair with Cú Chulainn was doomed as Cú Chulainn was mortal and Fand was the Queen of the Fairies. On her return to Manannán he shakes his cloak between Cú Chulainn and Fand, ensuring the two will never meet again. Manannán is known for creating mists and invisibility. As well as his magic to prevent Fand and Cú Chulainn ever seeing each other again he is known in legend to create mists that cover the Isle of Man and protect it from enemies.