Early Imperial campaigns in Germania in the context of "Clades Variana"

The wars of Augustus are the military campaigns undertaken by the Roman government during the sole rule of the founder-emperor Augustus (30 BC – AD 14). This was a period of 45 years when almost every year saw major campaigning, in some cases on a scale comparable to the Second Punic War (218–201 BC), when Roman manpower resources were stretched to the limit. This period also saw expansion through diplomacy and annexation, without the direct use of military force. The result was a major expansion of the empire that Augustus inherited from the Roman Republic, although the attempted conquest of Germania ended in defeat despite the enormous deployment of resources involved. As a result of these campaigns, the Roman Empire assumed the borders it would hold, with a few modifications, for its entire history.

Nero Claudius Drusus Germanicus (38–9 BC), commonly known in English as Drusus the Elder, was a Roman general and politician. He was a patrician Claudian but his mother was from a plebeian family. He was the son of Livia Drusilla and the stepson of her second husband, the Emperor Augustus. He was also brother of the Emperor Tiberius; the father of the Emperor Claudius and general Germanicus; paternal grandfather of the Emperor Caligula, and maternal great-grandfather of the Emperor Nero.

Drusus launched the first major Roman campaigns across the Rhine and began the conquest of Germania, becoming the first Roman general to reach the Weser and Elbe rivers. In 12 BC, he led a successful campaign into Germania, subjugating the Sicambri. 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. In 11 BC, he conquered the Usipetes and the Marsi, extending Roman control to the Upper Weser. In 10 BC, he launched a campaign against the Chatti and the resurgent Sicambri, subjugating both. The following year, while serving as consul, he conquered the Mattiaci and defeated the Marcomanni and the Cherusci, the latter near the Elbe. His Germanic campaigns were cut short in the summer of 9 BC by his death after a riding accident.

The 0s began on January 1, AD 1 and ended on December 31, AD 9, covering the first nine years of the Common Era.

In Europe, the 0s saw the continuation of conflict between the Roman Empire and Germanic tribes in the Early Imperial campaigns in Germania. Vinicius, Tiberius and Varus led Roman forces in multiple punitive campaigns, before sustaining a major defeat at the hands of Arminius in the Battle of the Teutoburg Forest. Concurrently, the Roman Empire fought the Bellum Batonianum against a rebelling alliance of native peoples led by Bato the Daesitiate in Illyricum, which was suppressed in AD 9. A conflict also took place in Korea, where Daeso, King of Dongbuyeo invaded Goguryeo with a 50,000-man army in AD 6. He was forced to retreat when heavy snow began to fall, stopping the conflict until the next decade. In China, the last ruler of the Chinese Western Han dynasty (Ruzi Ying) was deposed, allowing Wang Mang to establish the Xin dynasty.