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.