The 4th century is when we find the majority of non-weapon Roman artifacts outside of Roman territory, with a large number of Jewelry pieces, beads, glass ware, and coins being found in Germania, Scandinavia (especially coins, and while I discounted them earlier, this is also when the majority of Roman Weapons found in the region show up), while Roman Fashion evolved, adopted Breeches, Hose, and Trousers, likely due to a cooling Climate, and long sleeve tunics of greater length (knee length vs Mid Thigh), which were largely first adopted by the army, but spread to the civil and bureaucratic sections of society as well, and proved very favorable among many of the “Barbarian” peoples, who adopted them as well, and as they took over chunks of the Empire, these garments made assimilation into Roman Society easier (it’s also now recognized that the average person probably didn’t consider the empire to have fallen until at least 1-2 centuries after the Deposition of Romulus Augustus, with Germanic kings frequently taking the title “King of Romans” and people routinely referring to themselves as Roman well into the 700s, which was the result of the predecessors of these kings being given land as Feoderati and client kings), while Germanic and Celtic Weaponry evolved to adopt a much more Roman appearance, to the point that after the mid 4th century it becomes incredibly difficult to identify whether a weapon is Roman or Barbarian, while the increasing use of heavy cavalry among various warlords is the result of the Roman use of the Cataphract; furthermore, Roman Art becomes the basis for later medieval art, (while statues are often brought up as the iconic Roman art, the most common medium was paintings and mosaic, which were routinely copied by post Roman Kingdoms) and Roman coinage was regularly emulated for centuries to come, and the primary style of Post Roman Europe is what is known as “Romanesque” as it is very clearly an emulation of Roman Architecture, to the point some of it was believed to have been Roman originals