["Hera Ludovisi," 1st century CE, source: Wikimedia Commons]
She was born in Athens, shortly before her family moved back to Rome (minus her father, who had abandoned his wife). There she was raised by her mother, her aunt Livia Drusilla, and her uncle the Emperor Augustus. At age 20 she married Nero Claudius Drusus, younger brother of Tiberius. Three of the couple’s children survived to adulthood: Germanicus (husband of Agrippina Major), Livilla, and the future Emperor Claudius. When her husband died, she refused to remarry and raised her children with the help of her family.
She lost two of her children within two years of each other. Germanicus died in 19 CE while traveling with his wife, dashing hopes that he might become the next emperor. Antonia did not attend his funeral, possibly not of her own will if the historian Tacitus is to be believed. In 21 CE her daughter Livilla plotted with Sejanus, prefect of the Praetorian Guard, to overthrow Tiberius. When they were discovered, all involved were executed save Livilla, who was handed over to her mother and died shortly thereafter. Cassius Dio claims Antonia starved her.
In 37 CE, Antonia’s grandson Caligula became emperor. At first he honored her highly, giving her all of the honors Livia Drusilla had held, making her high priestess of Augustus, and granting her the privileges of a Vestal Virgin. She acted as one of his primary advisors, keeping him in line as best she could. Soon, however, a rift grew between them and he refused to listen to her anymore. Antonia died later that year. Among the causes of death suggested by Roman historians are poison and sheer outrage at her grandson’s treatment of her. Though Caligula paid her no honors after her death, her son Claudius granted her the title of Augusta and made her birthday a public holiday.