Mil Espaine was the son of Bile, son of Breogan. He was born and raised in Spain, where his ancestor, Lamfhind, a descendant of Goidel Glas, had settled. Mil was at first married to Saeng, daughter of a king of Scythia.(Ironically, Mil's ancestors had originally come frome Scythia.) Saeng bore Mil a son named Eber Donn. When Saeng died, Mil discovered that his father in-law was plotting against him. Having killed the Scythian king, Mil fled to Egypt where he married Scota. The couple then retuned to Spain, where Scota gave birth to their children, Erimon, Amergin, Eber Finn, Ir, and many others.

When Mil's uncle, Ith, discovered Ireland from the top of Brigantia, he decided to investigate this great discovery. Ith journeyed to Ireland, but was killed by the Tuatha de Danann. Mil died of unknown causes while Ith was journeying to Ireland, and both these deaths convinced Mil's sons that there was no point in living in Spain anymore. Thusly, the sons of Mil (more often called the Milesians), went on to conquer Ireland.