Antonia Minor was a daughter to Octavia the Younger by her second marriage to triumvir Mark Antony, and Octavia was the second eldest sister and full-blooded sister of Augustus. Germanicus' father, Drusus the Elder, was the second son of the Empress Livia Drusilla by her first marriage to praetor Tiberius Nero, and was the emperor Tiberius's younger brother and Augustus's stepson. In the year 9, Augustus ordered and forced Tiberius to adopt Germanicus, who happened to be Tiberius's nephew, as his son and heir. Germanicus was a favourite of his great-uncle Augustus, who hoped that Germanicus would succeed his uncle Tiberius, who was Augustus's own adopted son and heir. This in turn meant that Tiberius was also Agrippina's adoptive grandfather in addition to her paternal great-uncle. Birth and early life Agrippina was born on 6 November in AD 15, or possibly 14, at Oppidum Ubiorum, a Roman outpost on the Rhine River located in present-day Cologne, Germany. A second sister Julia Drusilla was born on 16 September 16, also in Germany. As a small child, Agrippina travelled with her parents throughout Germany (15–16) until she and her siblings (apart from Caligula) returned to Rome to live with and be raised by their maternal grandmother Antonia. Her parents departed for Syria in 18 to conduct official duties, and, according to Tacitus, the third and youngest sister was born en route on the island of Lesbos, namely Julia Livilla, probably on March 18. In October of AD 19, Germanicus died suddenly in Antioch (modern Antakya, Turkey). Germanicus' death caused much public grief in Rome, and gave rise to rumours that he had been murdered by Gnaeus Calpurnius Piso and Munatia Plancina on the orders of Tiberius, as his widow Agrippina the Elder returned to Rome with his ashes. Agrippina the Younger was thereafter supervised by her mother, her paternal grandmother Antonia Minor, and her great-grandmother, Livia, all of them notable, influential, and powerful figures from whom she learnt how to survive. She lived on the Palatine Hill in Rome. Her great-uncle Tiberius had already become emperor and the head of the family after the death of Augustus in 14. Marriage to Gnaeus Domitius Ahenobarbus After her thirteenth birthday in 28, Tiberius arranged for Agrippina to marry her paternal first cousin once removed Gnaeus Domitius Ahenobarbus and ordered the marriage to be celebrated in Rome. Domitius came from a distinguished family of consular