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.
Constitutional reforms of Augustus
With the legitimate government of the Republic defeated, Caesar set about initiating his own constitutional reforms. Caesar immediately set about consolidating the various offices of the Republic into himself. He was first appointed Dictator in 49 BC but resigned it within eleven days. In 48 BC, he was re-appointed dictator, only this time for an indefinite period, and in 46 BC, he was appointed dictator for ten years. Finally, in 44 BC, Caesar was appointed Dictator for life. In addition to holding the dictatorship, Caesar held the Consulship in 48 BC, 46 BC, 45 BC (without colleague), and 44 BC. By holding the Dicatorship and the Consulship simultaneously, Caesar's "imperium" ("military authority") was supreme and all provincial governors were subservant to his will. With his unchallengeable command authority, Caesar could remove any civil magistrate or military commander from office at his pleasure.