The exquisitely beautiful memoir of his father-in-law, in the introduction to which this passage occurs, was written by Tacitus in the year which succeeded his own consulship, and which saw the accession of Trajan. He was then already meditating a large historical work on the events of his own lifetime, for which he had, by reading and reflection, as well as by his own administrative experience, accumulated large materials. The essay _De Origine Situ Moribus ac Populis Germaniae_ was published about the same time or a little later, and no doubt represents part of the material which he had collected for the chapters of his history dealing with the German wars, and which, as much of it fell outside the scope of a general history of Rome, he found it worth his while to publish as a separate treatise. The scheme of his work became larger in the course of its progress. As he originally planned it, it was to begin with the accession of Galba, thus dealing with a period which fell entirely within his own lifetime, and indeed within his own recollection. But after completing his account of the six reigns from Galba to Domitian, he did not, as he had at first proposed, go on to those of Nerva and Trajan, but resumed his task at an earlier period, and composed an equally elaborate history of the empire from the death of Augustus down to the point where his earlier work began. He still cherished the hope of resuming his history from the accession of Nerva, but it is doubtful whether he lived long enough to do so. Allusions to the Eastern conquests of Trajan in the _Annals_ show that the work cannot have been published till after the year 115, and it would seem--though nothing is known as to the events or employments of his later life--that he did not long survive that date. But the thirty books of his _Annals_ and _Histories,_ themselves splendid work for a lifetime, gave the continuous history of the empire in the most crucial and on the whole the most remarkable period of its existence, the eighty-two years which succeeded the death of its founder.