Fedelm

In Táin Bó Cuailnge, a Connacht seer named Fedelm foretold the defeat of Medb's army that sought to fetch the Brown Bull of Cuailnge, in Ulster.

In the Tain, there is a description of her and the clothes she wore when she faced Medb. Fedelm was a young woman who wore a speckled cloak held by gold pin and a tunic with a red-embroidered hood. Her sandals had gold clasps. Fedelm had yellow hair in three tresses - two were wound upward around her head, while the third hung behind her, all the way down to her calves. She had a broad brow but a narrow jaw. Her eyebrows were dark and her eyelashes long. And her teeth were like an array of jewels. But the most amazing thing about Fedelm's features were her eyes: she had triple irises.

Fedelm rode in a chariot, drawn by two black horses. In her hand, she held a light gold weaving rod.

Fedelm had the skill of imbas forasnai or the Light of Foresight. The imbas forasnai was the talent of clairvoyance or divination, where prophecies would come to her in the form of a vision. She learned this and other druidical skills in Alba (name for Scotland in Gaelic).

Three times, Queen Medb of Connacht asked Fedelm what she saw when the seeress looked at her host, and three times her replies were "I see crimson. I see red." Medb didn't believe that was possible, because she knew that the men of Ulster would suffer from the Pang of Ulster, a curse that they would suffer for five days and four nights (or vice versa), because of the curse of Macha.

After her last reply to the queen, Fedelm explained in her song that one lone warrior (Cu Chulainn) would bar their path, delaying their march to raid the cattle of Daire Mac Fiachna and his prized bull long enough so that the Ulstermen would recover from their pang. The Ulstermen would then muster their mighty forces and defeat her army.

Despite the prophecy and warning, Medb had her army heedlessly march into Ulster to capture Brown Bull, and in the end, they suffered a terrible defeat.