Eriu Trinity Knot Celtic Watch. Freshwater river pearls bracelet with a crystal set silver-plated watch and an embossed trinity knot dial. Quartz movement with a 3 year battery. Eriu One of the three sisters, the divine goddesses of Ireland. When the Milesians invaded Ireland, Eriu and her sisters Banba and Fotla went to greet them, each wanting them to name the country after herself. They agreed that the country would bear Eriu's name. Eire is the modern Irish spelling of Eriu and Erin, an anglicized form.