Forgall Manach’s daughter and Mananann’s last wife. Conchobar wanted Cuchulainn to married her but Forgall didn’t agree and send Cuchulainn to Scathach. He was thinking Cuchulainn never come back. But the hero came back, fled with Emer and married her. A long time after, Emer was jealous of Fand, the mistress of Cuchulainn and wanted to kill her, but finally, she gave her pardon. Conchobar’s druid gave her the drink of everlasting forget.
In the Ulster Cycle of Irish mythology, Emer, or in modern Irish Eimear, daughter of Forgall the Wily, was Cúchulainn's wife.