Gloria is abl. limiting ingens.
Castra ac spatia. In apposition with lata vestigia==spatiosa castra or castrorum spatia, H. 704, II. 2; Z. 741.
Utraque ripa, sc. of the Rhine, the river and river bank by eminence.
Molem manusque. The mass of their population, and the number of their armies. Observe the alliteration, as if he had said: measure the mass and might.
Exitus, i.e. migrationis. Often used in this sense, cf. Caes. B.C. 3, 69: Salutem et exitum sibi pariebant.—Fidem, proof.
Sexcentesimum—annum. T. follows the Catonian Era. According to the Varronian Era, received by the moderns, the date would be A.U.C. 641 = A.C. 113.
Alterum—consulatum. The second consulship of Trajan (when he was also Emperor) was, after the reckoning of Tacitus, A.U.C. 850, according to modern computation, 851 = A.D. 98. This year doubtless marks the time when this treatise was written, else why selected?
Vincitur. So long is Germany in being conquered. (The work was never completed.) Cf. Liv. 9, 3: quem per annos jam prope triginta vincimus.
Medio—spatio. In the intervening period, sc. of 210 years.
Samnis—Galliaeve. The Romans had fought bloody, and some times disastrous battles with the Samnites (at the Caudine Forks, Liv. 9, 2.), with the Carthaginians (in the several Punic Wars), with the Spaniards under Viriathus and Sertorius (Florus, Lib. 2.), with the Gauls (Caes. B.G. pass.). But none of these were so sanguinary as their wars with the Germans.