Question: Who is Julia Iotapa (Daughter Of Antiochus Iii)'s paternal grandfather?
Sentence (from "Julia Iotapa (daughter of Antiochus III)"): Julia Iotapa, or simply Iotapa (before 17 – around 52), daughter of King Antiochus III of Commagene, was Queen of Commagene, consort of her King brother Antiochus IV.
Relevant evidence: Yes