Question: Who is the paternal grandmother of Nath Í Mac Fiachrach?
Sentence (from "Nath Í mac Fiachrach"): Nath Í, also known as Dathí, son of Fiachrae, son of Eochaid Mugmedon, was a semi-historical Irish king of the 5th century, the father of the likely-historical king Ailill Molt and the ancestor of the Uí Fiachrach dynasties of early medieval Connacht.
Relevant evidence: Yes