Firmly based on ancient literature and material evidence, this illustrated biography assesses the life of Agrippina the Younger (15–59 CE). Agrippina was declared "unique" by Tacitus, ancient Rome's most insightful political historian, both for her own political standing and as the daughter of a triumphing general and the sister, wife, and mother of emperors--respectively, Caligula (r. 37–41), Claudius (r. 41–54), and Nero (r. 54–68). Tacitus and other ancient historians depict her with horrified fascination as they vividly chart her growing presence through tumultuous vicissitudes, ending with her murder by her son Nero in 59. Documentary evidence corroborates Agrippina as extraordinary. Among other "firsts," she is the first woman to be portrayed and identified on coins while alive; the first woman whose name is given to a veteran colony; and she appeared in more numerous statuary installations than known for earlier women. Agrippina's life sheds light on Rome's evolution into a monarchy dominated by her family; it also illuminates the endurance of Rome's ancestral patriarchy, showing the tight limits of power even for imperial women. Assessment of her reception up to the twentieth century highlights the importance of Tacitus for our understanding of this remarkable political creature. Neither damning nor glorifying Agrippina, this biography sensitively relies on ancient evidence to tell her story.