Political map of Europe & the Mediterranean 24 October 79 AD (Agri Decumates): Following his reorganization of the eastern Roman provinces, Vespasian turned to securing the west. In 74 AD he began the settlement and fortification of the Agri Decumates—the part of Germania lying between the upper Rhine and Danube rivers. The colonization of this region would continue long after Vespasian’s death in 79 AD, with Roman expansion into the Agri Decumates only ending at around the time of the accession of Marcus Aurelius (161).