Germanicus's expedition into Germania

Historical context

In 4 AD, Augustus forced Tiberius, who had just returned from exile and been adopted by the emperor, to adopt his own nephew Germanicus Julius Caesar. This happened even though Tiberius already had a biological son, Drusus Minor, who was only a year younger. The adoption ceremony took place on June 26, and Augustus had over a million sesterces handed out to the soldiers. Tiberius’s return to power brought stability to the empire and renewed the push for conquest beyond its borders.

In the autumn of 9 AD, the Cheruscan prince Arminius led Germanic forces to destroy three Roman legions—the XVII, XVIII, and XIX—in the Teutoburg Forest. This wiped out three of the five legions stationed on the Rhine. Augustus immediately sent Tiberius across the Alps to secure the frontier, worried that the Germanic tribes might invade Gaul or Italy, but those fears turned out to be groundless. By 10 AD, the two surviving legions were reinforced with six more.

On the Lower Rhine, the legions were I Germanica, V Alaudae, XX Valeria Victrix, and XXI Rapax; on the Upper Rhine, II Augusta, XIII Gemina, XIV Gemina, and XVI Gallica. It is unclear whether the I and V legions were the ones that escaped the disaster or if the XIII and XIV were. Auxiliary forces were also beefed up: Tacitus records 26 cohorts and 8 alae by 14 AD. The total Rhine army from 10 AD onward likely numbered about 80,000 men, with allied tribes contributing additional warriors when needed.

Campaigns pushed deeper into Germania in 11 and 12 AD. Legionaries rebuilt bases east of the Rhine, cut wide clearings as limites, and created a depopulated buffer zone. Naval operations on the North Sea kept coastal tribes loyal.

Timeline, 15 AD

At the end of Germanicus' first campaign in the Marsi, Tiberius decided to award him a triumph while the war was still being fought. Germanicus prepared the new campaign of 15 AD, anticipating operations to spring and attacking the Chatti first. He hoped to divide the enemy into a pro-Roman part led by Segestes, Arminius' father-in-law, and a hostile part led by Arminius. Germanicus divided the army into two columns.

The first, under Aulus Caecina Severus, moved from Castra Vetera with vexillationes of 4 legions of Lower Germany, including 5,000 auxiliaries and some German allies. The second, led by Germanicus, moved from Mogontiacum with vexillationes of the 4 legions of Upper Germany and double the number of German allies. The mutiny of the legions offered Arminius an opportunity to settle accounts with the internal enemy. In 9 AD, Segestes had warned Varus of Arminius' attack plans, but in vain.

The enmity between the princely families took on a personal note when Arminius married Segestes' daughter Thusnelda against Segestes' wishes. In autumn/winter of 14 AD, Arminius took action against Segestes, but Segestes initially seemed to gain the upper hand. Germanicus hoped the Arminius coalition would collapse and attacked in the spring, targeting the Chatti, whose princely houses were related to those of the Cherusci.

Timeline, 16 AD

In 16 AD, the aim was to destroy the enemy. A bloody and merciless offensive war reached its climax. The main opponents were the Cherusci, to be attacked in their core areas on the upper Weser and in the Leine valley. Tacitus has Germanicus make strategic considerations: forests and swamps, and the short summer, were advantageous for the Germanic tribes; field battles in open terrain were disadvantageous.

For the Romans, long marches, consumption of weapons, long baggage columns, and exhausted Gallic horse resources were problematic. The sea route offered a solution: legions and provisions could be transported together, campaigns could begin earlier, horses were spared, and the element of surprise allowed legions to advance deep into Germania via North German rivers. The Germanic tribes habitually attacked Romans on their return marches. A fleet improved logistical possibilities and shortened the retreat.

Germanicus ordered the equipment of a fleet of 1,000 ships. Some transports were short with broad hulls and narrow bow and stern; some had flat keels to run aground; several had rudders fore and aft; many had decks for horses, provisions, and guns. While ships were prepared, Germanicus ordered operations against tribes near the Rhine. The legate Gaius Silius marched from Mainz against the Chatti, capturing the wife and daughter of the Chatti prince Arpus.

Balance and Consequences

Germanicus' successes included at least two major battle victories (Idistaviso and Angrivarii Wall), retrieval of two of Varus' eagles, captures including Arminius' pregnant wife, burial of Varus' army, pushing tribes near the Rhine into the interior, and devastation and revenge campaigns. Control over coastal tribes was retained or regained; the Angrivarii and individual tribal chiefs were subjugated. These were offset by enormous losses. The historian Reinhard Wolters assumes almost as many soldiers fell under Germanicus as in all Germanic Wars since 12 BC, including Varus' catastrophe.

Peter Kehne estimates losses at 20,000 to 25,000 men. For the Romans, the dismissal of Germanicus ended the military offensive policy. The concentration of troops in Xanten and Mainz was reduced, and the unified supreme command of the Rhine army ended. Bases on the right bank of the Rhine were abandoned, except for a few places on the North Sea coast and in front of Mainz.

Influence on the tribal world continued with diplomacy, money, and contacts with old allies. Germanic losses were extremely heavy, but no accurate estimates were made.

Arminius died in 19 or 21 AD, against whom tribes dissatisfied with his claims to pan-Germanic power rebelled. The leader of the Chatti, Adgandestrius, offered the Romans to eliminate Arminius if the empire sent poison; the Senate and princeps refused. Arminius soon fell victim to a conspiracy of his close associates, and the Senate granted Drusus the Younger a triumph.

Did You Know?

• The ancient authors hardly addressed the campaigns of Germanicus and at most reported on the triumphal procession of Germanicus in 17 AD.
• According to Strabo, prisoners from subjugated tribes taken in the triumphal procession included the Kaulki, Ampsivarii, Bructerii, Usipetii, Cherusci, Chatti, Chattuarii, Landii, and Tubattii.