Angrivarii
The wars began in the last years of the reign of Augustus, first emperor of Rome. Augustus died an old but respected man in the year 14 and was celebrated with much pomp and splendor. He left a document to be read to the senate posthumously, expressly forbidding extension of the empire beyond the Rhine. News of the will was welcomed by the Germans, thinking it gave them a free hand in the region. Germanicus found it necessary to pacify the border, which he did by a combination of scorched earth raids and offers of alliance with Rome - in short, stick and carrot. These raids also kept the army of the lower Rhine distracted from the possibility of mutiny, which had broken out on Augustus's death and only been quelled by concessions and executions.
Julio-Claudian dynasty
Although Augustus' succession plans were all but ruined due to the deaths of more than several family members, including many of his own descendants, in the end Tiberius remained faithful to his predecessor's wishes that the next emperor would hail from the Julian side of the Imperial family. Thus, Tiberius was succeeded by Gaius Julius Caesar Augustus Germanicus, the sole-remaining son of his adopted son Germanicus. The new emperor not only belonged to both the Julian and Claudian sides of the Imperial family, but was also a direct descendant of Augustus Caesar through his mother Agrippina the Elder. More commonly remembered in history by his childhood nickname Caligula, he was the third Roman Emperor ruling from AD 37 to 41.