VELLEIUS PATERCULUS, History of Rome
[II.XCVI] Mors deinde Agrippae, qui nouitatem suam multis rebus nobilitauerat atque in hoc perduxerat ut et Neronis esset socer, cuiusque liberos nepotes suos diuus Augustus, praepositis Gai ac Lucii nominibus, adoptauerat, admouit propius Neronem Caesari: quippe filia Iulia eius, quae fuerat Agrippae nupta, Neroni nupsit. Subinde bellum Pannonicum, quod inchoatum ab Agrippa Marcoque Vinicio, auo tuo, consulari, magnum atroxque et perquam uicinum imminebat Italiae, per Neronem gestum est. Gentes Pannoniorum Delmatarumque nationes situmque regionum ac fluminum numerumque et modum uirium excelsissimasque et multiplices eo bello uictorias tanti imperatoris alio loco explicabimus: hoc opus seruet formam suam. Huius uictoriae compos Nero ouans triumphauit.
[2.96] Then occurred the death of Agrippa. Though a "new man" he had by his many achievements brought distinction upon his obscure birth, even to the extent of becoming the father-in-law of Tiberius; and his sons, the grandsons of the emperor, had been adopted by Augustus under the names of Gaius and Lucius. His death brought Tiberius closer to Caesar, since his daughter Julia who had been married to Agrippa now married Tiberius.Shortly after,the Pannonian War, which had been begun by Agrippa in the consulship of your grandfather, Marcus Vinicius, was conducted by Tiberius, a war which was important and formidable enough and on account of its proximity, a menace to Italy. In another place I shall describe the tribes of the Pannonians and the races of the Dalmatians, the situation of their country and its rivers, the number and extent of their forces, and the many glorious victories won in the course of the war by the great commander; my present work must keep to its design. After achieving this victory, Tiberius celebrated an ovation.