Livia Drusilla (lĭvˈēə drōsĭlˈə) [key], c.55 B.C.–A.D. 29, Roman matron; mother of the Roman emperor Tiberius. She first married Tiberius Claudius Nero. Tiberius was his son. In 38 B.C., Augustus forced her husband to divorce her so that he might marry her himself. Her son Drusus Senior (see Drusus), born soon after her remarriage, was not the son of Augustus but of her first husband. On the accession of her son Tiberius, Livia Drusilla attempted unsuccessfully to control the government. She was known for her dignity, intelligence, and ambition.