Quick questions on Augustus's foreign policy and the imperial frontiers: HSC Ancient History

The Iberian peninsula had been Roman since the 2nd century BC but the north-western mountain regions resisted. Augustus campaigned in person (26-25 BC) and the wars were completed under Agrippa in 19 BC. The provinces of Hispania Tarraconensis, Lusitania, and Baetica were stabilised. The temple of Janus was closed in 25 BC to mark the (premature) peace.

Tiberius and his brother Drusus the Elder conducted the Alpine campaigns. They subjugated the Raetian, Vindelician, and other Alpine tribes, securing the routes between Italy and Gaul. The Trophy of the Alps (Tropaeum Alpium, dedicated 6 BC at La Turbie above Monaco) commemorated the victory with a tower and an inscription listing 45 conquered tribes.

Pannonia (12-9 BC). Tiberius conquered Pannonia, pushing the frontier to the Danube.

Drusus the Elder (12-9 BC). Augustus's stepson Drusus (younger brother of Tiberius) campaigned across the Rhine to advance the frontier toward the Elbe. He reached the Elbe in 9 BC but died after a fall from his horse on the return journey.

The Parthian Empire to the east was Rome's only peer-rival. Crassus had been defeated and killed at the Battle of Carrhae (53 BC) with 30,000 Romans lost and seven legionary eagles captured. Antony had failed in Parthia in 36 BC.

Egypt, annexed in 30 BC, was administered by an equestrian prefect under direct imperial control. The wealth of Egypt was effectively Augustus's personal resource.

Tacitus (Annals 1.11) reports Augustus's posthumous advice to Tiberius: keep the empire within its existing frontiers. The Teutoburg disaster had taught the limits of further expansion. The frontiers Augustus established (Rhine, Danube, Euphrates, the African desert margins) remained essentially stable for over two centuries.

Adrian Goldsworthy (Augustus, 2014) treats the early reign as ambitious expansion and the later reign (after Teutoburg) as defensive consolidation.

Tiberius conquered Pannonia, pushing the frontier to the Danube.

Conquered under Crassus the Younger.

Tiberius and others pacified the western Balkans.

A massive rebellion in Pannonia and Dalmatia required substantial Roman resources. Tiberius led the response. Suetonius (Tiberius 16) describes the war as the heaviest fighting since the Punic wars.

Augustus's stepson Drusus (younger brother of Tiberius) campaigned across the Rhine to advance the frontier toward the Elbe. He reached the Elbe in 9 BC but died after a fall from his horse on the return journey.

Continued the German campaigns intermittently.

Publius Quinctilius Varus, governor of Germania, was marching three legions (XVII, XVIII, XIX) back from summer campaigns to winter quarters when he was ambushed in the Teutoburg Forest by the Cherusci leader Arminius (a Romanised German with Roman citizenship who had served as an auxiliary commander). Over three days the Roman army was destroyed in dense forest under heavy rain. Around 15,000 to 20,000 Romans died.