Question: Who is Germanicus's maternal grandfather?
Sentence (from "Antonia Minor"): She was additionally the maternal great-aunt of the Empress Valeria Messalina and Faustus Cornelius Sulla Felix, the paternal grandmother of Claudia Antonia, Claudia Octavia, and Britannicus and the maternal grandmother of Julia Livia and Tiberius Gemellus.
Relevant evidence: No