Germanicus' campaign against the Germanic coalition was the opponent of
Arminius in 14–16 CE Though the shock at the slaughter was enormous, the Romans immediately began a slow, systematic process of preparing for the reconquest of the country. In 14 AD, just after Augustus' death and the accession of his heir and stepson Tiberius, a massive raid was conducted by the new emperor's nephew
Germanicus. He attacked the Marsi with the element of surprise. The Bructeri,
Tubanti and
Usipeti were roused by the attack and ambushed Germanicus on the way to his winter quarters, but were defeated with heavy losses. The next year was marked by two major campaigns and several smaller battles with a large army estimated at 55,000–70,000 men, backed by naval forces. In spring 15 AD,
Legatus Caecina Severus invaded the Marsi a second time with about 25,000–30,000 men, causing great havoc. Meanwhile, Germanicus' troops had built a fort on Mount
Taunus from where he marched with about 30,000–35,000 men against the Chatti. Many of the men fled across a river and dispersed themselves in the forests. Germanicus next marched on
Mattium ("caput gentis", capital city) and burned it to the ground. After initial successful skirmishes in summer 15 AD, including the capture of Arminius' wife
Thusnelda, the army visited the site of the first battle. According to Tacitus, they found heaps of bleached bones and severed skulls nailed to trees, which they buried, "...looking on all as kinsfolk and of their own blood...". At a location Tacitus calls the
pontes longi ("long causeways"), in boggy lowlands somewhere near the Ems, Arminius' troops
attacked the Romans. Arminius initially caught Germanicus' cavalry in a trap, inflicting heavy casualties, but the Roman infantry reinforced the rout and checked them. The fighting lasted for two days, with neither side achieving a decisive victory. Germanicus' forces withdrew and returned to the Rhine. Under Germanicus, the Romans marched another army, along with allied Germanic auxiliaries, into Germania in 16 AD. He forced a crossing of the Weser near modern
Minden, suffering losses to a Germanic skirmishing force, and forced Arminius' army to stand in open battle at
Idistaviso in the
Battle of the Weser River. Germanicus' legions inflicted huge casualties on the Germanic armies.
A final battle was fought at the
Angrivarian Wall west of modern
Hanover, repeating the pattern of high Germanic fatalities, which forced them to flee beyond the Elbe. Germanicus, having defeated the forces between the Rhine and the Elbe, then ordered
Caius Silius to march against the Chatti with a mixed force of three thousand cavalry and thirty thousand infantry and lay waste to their territory, while Germanicus, with a larger army, invaded the Marsi for the third time and devastated their land, encountering no resistance. With his main objectives reached and winter approaching, Germanicus ordered his army back to their winter camps, with the fleet incurring some damage from a storm in the North Sea. Afterwards, a few more raids across the Rhine resulted in the recovery of two of the three
legions' eagles lost in 9 AD: one Legion Eagle was recovered from the
Marsi in 14 AD; the Legion XIX Eagle was recovered from the
Bructeri in 15 AD by troops under Lucius Stertinius. Tiberius ordered the Roman forces to halt and withdraw across the Rhine. Germanicus was recalled to Rome and informed by Tiberius that he would be given a triumph and reassigned to a new command. Germania 14 Germanico.jpg|Military action in 14 CE Germania 15 Germanico.jpg|Campaigns in 15 CE Germania 16 Germanico.jpg|Operations in 16 CE Germanicus' campaign had been taken to avenge the Teutoburg slaughter and also partially in reaction to indications of mutinous intent amongst his troops. Arminius, who had been considered a very real threat to stability by Rome, was now defeated. Once his Germanic coalition had been broken and
honour avenged, the huge cost and risk of keeping the Roman army operating beyond the Rhine was not worth any likely benefit to be gained.
Later campaigns on display in the
Temple of Mars the Avenger in Rome holding an aquila The third legionary standard was recovered in 41 AD by Publius Gabinius from the Chauci during the reign of
Claudius, brother of Germanicus. Possibly the recovered
aquilae were placed within the
Temple of Mars Ultor ("
Mars the Avenger"), the ruins of which stand today in the
Forum of Augustus by the
Via dei Fori Imperiali in Rome. The last chapter was recounted by the historian Tacitus. Around 50 AD, bands of Chatti invaded Roman territory in
Germania Superior, possibly an area in Hesse east of the Rhine that the Romans appear to have still held, and began to plunder. The Roman commander,
Publius Pomponius Secundus, and a legionary force supported by Roman cavalry recruited auxiliaries from the
Vangiones and
Nemetes. They attacked the Chatti from both sides and defeated them, and joyfully found and liberated Roman prisoners, including some from Varus' legions who had been held for 40 years. Arminius continued to fight against the Romans, but the conflict remained a stalemate. He was poisoned by his fellow Germanics in 21 AD, possibly by his own family, who feared his increasing autocracy. ==Impact on Roman expansion==