The last general to lead Roman forces in the region during this time was Germanicus, the adoptive son of Emperor Tiberius, who in AD 16 had launched the final major military expedition by Rome into Germania.

This defeat convinced Augustus to reorganize and improve the military presence in Gaul in order to prepare the region for campaigns across the Rhine.

In preparation for the coming campaigns, Augustus established a mint at Lugdunum (Lyon) in Gaul, to supply a means of coining money to pay the soldiers, organized a census for collecting taxes from Gaul, and coordinated the establishment of military bases on the west bank of the Rhine.

On the return trip, Drusus' legions were nearly destroyed at Arbalo by Cherusci warriors taking advantage of the terrain to harass them.

[7] He was made consul for the following year, and it was voted that the doors to the Temple of Janus be closed, a sign the empire was at peace.

Velleius Paterculus portrays Germany as essentially conquered,[12] and Cassiodorus writing in the 6th century AD asserts that all Germans living between the Elbe and the Rhine had submitted to Roman power.

While the elite members of one faction sought stronger ties with Roman leaders, the Cherusci as a whole would continue to resist for the next twenty years.

Although Ahenobarbus had marched to the Elbe and directed the construction of infrastructure in the region east of the Rhine, he did not do well against the Cherusci warrior bands, who he tried to handle like Tiberius had the Sicambri.

Augustus recalled Ahenobarbus to Rome in 2 BC and replaced him with a more seasoned military commander, Marcus Vinicius.

At around the time of his appointment, many of the Germanic tribes arose in what the historian Velleius Paterculus calls the "vast war".

This accomplished a demonstration to his troops, to Rome, and to the German peoples that his army could move largely unopposed through Germany, but like Drusus, he did nothing to hold territory.

Tiberius lent support to this ruling clan to gain control over the Cherusci, and he granted the tribe a free status among the German peoples.

[20][21][22] Part of the Roman strategy was to resettle troublesome tribal peoples, to move them to locations where Rome could keep better tabs on them and away from their regular allies.

Following Tiberius's departure to Illyricum, Augustus appointed Publius Quinctilius Varus to the German command, as he was an experienced officer, but not the great military leader a serious threat would warrant.

On their way back to Castra Vetera, Varus received reports from Arminius that there was a small uprising west of the Roman camp.

Varus departed to deal with the revolt believing that Arminius would ride ahead to garner the support of his tribesmen for the Roman cause.

This pushed the soldiers at the front further into the enemy, and thousands of German warriors began to pour out of the woods to attack up close.

A few Romans survived and made their way back to the winter quarters at Xanten by staying hidden and carefully travelling through the forests.

After word reached Rome of Varus' defeat, Augustus had Tiberius sent back to the Rhine to stabilize the frontier in AD 10.

He says Tiberius:[34][35] penetrat interius, aperit limites, vastat agros, urit domos, fundit obvios maximaque cum gloria, incolumi omnium, quos transduxerat, numero in hiberna revertitur.

[35] penetrated into the heart of the country, opened up military roads, devastated fields, burned houses, routed those who came against him, and, without loss to the troops with which he had crossed, he returned, covered with glory, to winter quarters.

However, the campaign, combined with Rome's alliance to the Marcommanic federation of Marbod, prevented the Germanic coalition, led by Arminius, from crossing the Rhine to invade Gaul and Italy.

[42] Roman writers, including Tacitus and Cassius Dio, mention that Augustus left a statement ordering the end of imperial expansion.

It's not known if Augustus actually made such an order, or if Tiberius found it necessary to stop Roman expansion as the costs were too great, both financially and militarily.

The war culminated in AD 16 with the decisive victories of Battle of Idistaviso and Angrivarian Wall in which the Germanic coalition under Arminius was destroyed.

Rome handed annexed lands over to friendly chieftains and withdrew from most of Germany, as they felt the military effort required to continue was too great in comparison to any potential gain.

[44] Tiberius decided to suspend all military activities beyond the Rhine, leaving the German tribes to dispute over their territories and fight amongst each other.

[45] It is possible that a new attempt to invade Germania took place during the reign of Claudius, with the expedition of Corbulo in 47, which was stopped in its tracks after initial successes against the Frisians and Chaucis.

[46][47] It is not until Domitian that new territories were acquired, between the high valleys of the Rhine and the Danube, following the campaigns carried out by his generals between 83 and 85 (in what was called the Agri Decumates).

[50] The Roman Empire would launch no other major incursion into Germania Magna until Marcus Aurelius (r. 161–180) during the Marcomannic Wars.