of her younger grandchildren Caligula, Agrippina the Younger, Julia Drusilla, Julia Livilla, and later Claudia Antonia. Conflict with Livilla In 31 AD, a plot by her daughter Livilla and Tiberius’ notorious Praetorian prefect, Sejanus, to murder the Emperor Tiberius and Caligula and to seize the throne for themselves, was exposed by Apicata, the estranged ex-wife of Sejanus. Livilla allegedly poisoned her husband, Tiberius' son, Drusus Julius Caesar (nicknamed "Castor"), in 23 AD to remove him as a rival. Sejanus was executed before Livilla was implicated in the crime. After Apicata's accusation, which came in the form of a letter to the emperor, several co-conspirators were executed while Livilla was handed over to her formidable mother for punishment. Cassius Dio states that Antonia imprisoned Livilla in her room until she starved to death. Succession of Caligula and death When Tiberius died, Caligula became emperor in March 37 AD. Caligula awarded her a senatorial decree, granting her all the honors that Livia Drusilla had received in her lifetime. She was also offered the title of Augusta, previously only given to Augustus's wife Livia, but rejected it. Antonia would often offer Caligula advice, but he once told her, "I can treat anyone exactly as I please!" Having had enough of Caligula's anger at her criticisms and of his behavior, she committed suicide. Suetonius Caligula 23, relates how he might have poisoned her.When his grandmother Antonia asked for a private interview, he refused it except in the presence of the prefect Macro, and by such indignities and annoyances he caused her death; although some think that he also gave her poison. After she was dead, he paid her no honour, but viewed her burning pyre from his dining-room. Antonia died on 1 May 37. When Claudius became emperor after his nephew's assassination in 41 AD, he gave his mother the title of Augusta. Her birthday became a public holiday, which had yearly games and public sacrifices held. An image of her was paraded in a carriage. Cultural depictions She is remembered in De Mulieribus Claris, a collection of biographies of historical and mythological women by the Florentine author Giovanni Boccaccio, composed in 136162. It is notable as the first collection devoted exclusively to biographies of women in Western literature. Antonia is one of the main characters in the novel I, Claudius. In the television adaptation of the book she is portrayed by Margaret Tyzack.