Later that year he led a naval expedition against Germanic tribes along the North Sea coast, conquering the Batavi and the Frisii, and defeating the Chauci near the mouth of the Weser.

Drusus was the youngest son of Livia Drusilla from her marriage to Tiberius Claudius Nero, who was legally declared his father before the couple divorced.

Simpson asserted that there are three moments in history where the name change is probable to have happened; when his brother Tiberius was adopted by Marcus Gallius, when their father died in 33 BC, or when he assumed the toga virilis.

[16] Simpson stated that in his opinion Livia chose the names Decimus and Drusus for her younger son to minimize association with her ex-husband after she married Octavian due to the former's poor status at the time, but that several years after the man's death it was opportune to emphasize her younger son's connection with his elder brother and that the name change was probably done upon him assuming the toga virilis.

Since Seutonius makes it clear that Tiberius did use Gallius name (although briefly) but dropped it out of respect for his step-father the adoption must have happened before Drusus was born.

[20] Klaus Scherberich is critical of Mottershead's proposal, he argues that there are no examples of a conservative patrician family like the Claudii Nerones adopting a completely new praenomen from a maternal ancestor, especially when said gentes were non-patrician.

[8] Lindsay Powell believes that Drusus personally (despite his young age) may have changed his name directly after his father's death to preserve and honor his memory.

[24] His contribution to the ongoing building and urban development in Gaul can be seen in the establishment of the pes Drusianus, or ‘Drusian foot’, of about 33.3 cm (13.1 in), which was in use in Samarobriva (modern Amiens) and among the Tungri.

[26] As governor of Gaul, Drusus made his headquarters at Lugdunum, where he decided to establish the concilium Galliarum or ‘council of the Gaulish provinces’ sometime between 14 and 12 BC.

[27] This council would elect from its members a priest to celebrate games and venerate Rome and Augustus as deities[28] every 1 August at the altar of the three Gauls that Drusus established at Condate in 10 BC.

[32] In spring of 12 BC, he embarked an expeditionary force, perhaps consisting of the Legiones I Germanica and V Alaudae, by ship from the vicinity of modern Nijmegen, making use of one or more canals he had built for the purpose.

[36] Drusus' forces defeated the Bructeri, but, as it was now late in the campaign season, turned back for their winter quarters in Gaul, taking advantage of their new alliance with the Frisii to navigate through the difficult conditions on the North Sea.

This time, he assembled a force consisting of all or part of five legions in addition to auxiliaries and, setting out from Vetera on the Rhine, ascended the River Lippe.

[38] He reached the Werra Valley before deciding to turn back for the season, as winter was coming on, supplies were dwindling, and the omens were unfavorable.

[40] The Cherusci failed to capitalize on their initial advantage, whereupon the Romans broke through their lines, defeated the Germanic attackers, and acclaimed Drusus as imperator.

[40] To show his continued mastery of the ground, Drusus garrisoned a number of positions within Germania during the winter of 11–10 BC, including one somewhere in Hesse[41] and one in Cheruscan territory, probably either the camp at Haltern or that at Bergkamen-Oberaden,[42] both in present-day North Rhine–Westphalia.

[41] Drusus was given the honor of an ovation, and for the third time, Augustus closed the doors of the Temple of Janus, signifying that the whole Roman world was then at peace.

Drusus pursued them, proceeding from the sites of present-day Mainz and Rödgen, where he set up a base of supply, to Hedemünden, where a strong new camp was established.

[45] Around this time, the canny Marcomannic king Maroboduus responded to the Roman incursion by relocating his people en masse to Bohemia.

[46] In summer of 10 BC, Drusus left the field in order to return to Lugdunum, where he inaugurated the sanctuary of the Three Gaulish provinces at Condate on 1 August.

His consulship conferred the chance for Drusus to attain Rome's highest and rarest military honor, the spolia opima, or spoils of an enemy chieftain slain personally by an opposing Roman general who was fighting (as consuls did) under his own auspices.

[49] He quickly returned to the field, stopping to confer with his staff at Lugdunum and to dedicate a temple to Caesar Augustus at Andemantunnum, before rejoining his command at Mainz, from which the year's expedition departed in early spring.

[53] Drusus had sought out multiple Germanic (at least three) chieftains during his campaigns in Germany (12 BC–9 BC), engaging them in "dazzling displays of single combat".

Rich suggests that this action was done as an affirmation to Drusus' memory; had the young commander lived, he would have placed spolia opima in the temple himself.