Question: Who is Abu Ishaq Ibrahim's paternal grandfather?
Sentence (from "Mu'izz al-Dawla"): Ahmad ibn Buya (Persian: احمد بن بویه, died April 8, 967), after 945 better known by his "laqab" of Mu'izz al-Dawla ("Fortifier of the Dynasty"), was the first of the Buyid emirs of Iraq, ruling from 945 until his death.
Relevant evidence: Yes