Tiberius succeeded to the command left vacant by the death of his brother Drusus. Less daring, but of a more cautious and scheming nature, he began by taking possession of the land of the Sicambrians and colonizing a part of the tribe on the west bank of the Rhine. He then gradually extended his power, and in the course of two years brought nearly the whole country between the Rhine and Weser under the rule of Rome. His successor, Domitius Ænobarbus, built military roads through Westphalia and the low, marshy plains towards the sea. These roads, which were called "long bridges," were probably made of logs, like the "corduroy" roads of our Western States, but they were of great service during the later Roman campaigns. After the lapse of ten years, however, the subjugated tribes between the Rhine and the Weser rose in revolt. The struggle lasted for three years more, without being decided; and then Augustus sent Tiberius a second time to Germany. The latter was as successful as at first: he crushed some of the rebellious tribes, accepted the submission of others, and, supported by a fleet which reached the Elbe and ascended that river to meet him, secured, as he supposed, the sway of Rome over nearly the whole of _Germania Magna_. This was in the fifth year of the Christian Era. Of the German tribes who still remained independent, there were the Semnones, Saxons and Angles, east of the Elbe, and the Burgundians, Vandals and Goths along the shore of the Baltic, together with one powerful tribe in Bohemia. The latter, the Marcomanni, who seem to have left their original home in Baden and Würtemberg on account of the approach of the Romans, now felt that their independence was a second time seriously threatened. Their first measure of defence, therefore, was to strengthen themselves by alliances with kindred tribes. [Sidenote: 8 B. C. THE MARCOMANNI: VARUS.] The chief of the Marcomanni, named Marbod, was a man of unusual capacity and energy. It seems that he was educated as a Roman, but under what circumstances is not stated. This rendered him a more dangerous enemy, though it also made him an object of suspicion, and perhaps jealousy, to the other German chieftains. Nevertheless, he succeeded in uniting nearly all the independent tribes east of the Elbe under his command, and in organizing a standing army of 70,000 foot and 4,000 horse, which, disciplined like the Roman legions, might be considered a match for an equal number. His success created so much anxiety in Rome, that in the next year after Tiberius returned from his successes in Germany, Augustus determined to send a force of twelve legions against Marbod. Precisely at this time, a great insurrection broke out in Dalmatia and Pannonia, and when it was suppressed, after a struggle of three years, the Romans found it prudent to offer peace to Marbod, and he to accept it.