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.
Lucretia
The constitutional consequences of this event were, formally at least, to reverberate for more than two thousand years. Rome would never again have a hereditary "king," even if later emperors were absolute rulers in all but name. This constitutional tradition prevented both Julius Caesar and Octavian Augustus from accepting a crown; instead they had to devise a confluence of several republican offices onto their persons in order to secure absolute power. Their successors both in Rome and in Constantinople adhered to this tradition in form if not in essence, and even the office of German Holy Roman Emperor remained typically elective rather than hereditary—up to its abolition in the Napoleonic Wars, 2314 years later.