Alps in 16 BC was another important victory for Rome, since it provided a large territorial buffer between the Roman citizens of Italy and Rome's enemies in Germania to the north. Horace dedicated an ode to the victory, while the monumental Trophy of Augustus near Monaco was built to honor the occasion. The capture of the Alpine region also served the next offensive in 12 BC, when Tiberius began the offensive against the Pannonian tribes of Illyricum, and his brother Nero Claudius Drusus moved against the Germanic tribes of the eastern Rhineland. Both campaigns were successful, as Drusus's forces reached the Elbe River by 9 BC—though he died shortly after by falling off his horse. It was recorded that the pious Tiberius walked in front of his brother's body all the way back to Rome. To protect Rome's eastern territories from the Parthian Empire, Augustus relied on the client states of the east to act as territorial buffers and areas that could raise their own troops for defense. To ensure security of the empire's eastern flank, Augustus stationed a Roman army in Syria, while his skilled stepson Tiberius negotiated with the Parthians as Rome's diplomat to the East. Tiberius was responsible for restoring Tigranes V to the throne of the Kingdom of Armenia. Arguably his greatest diplomatic achievement was negotiating with Phraates IV of Parthia (37–2 BC) in 20 BC for the return of the battle standards lost by Crassus in the Battle of Carrhae, a symbolic victory and great boost of morale for Rome. Werner Eck claims that this was a great disappointment for Romans seeking to avenge Crassus's defeat by military means. However, Maria Brosius explains that Augustus used the return of the standards as propaganda symbolizing the submission of Parthia to Rome. The event was celebrated in art such as the breastplate design on the statue Augustus of Prima Porta and in monuments such as the Temple of Mars Ultor ('Mars the Avenger') built to house the standards. Parthia had always posed a threat to Rome in the east, but the real battlefront was along the Rhine and Danube rivers. Before the final fight with Antony, Octavian's campaigns against the tribes in Dalmatia were the first step in expanding Roman dominions to the Danube. Victory in battle was not always a permanent success, as newly conquered territories were constantly retaken by Rome's enemies in Germania. A prime