556. Decline of civilisations
Among the invaders, the Visigoths were on the run for the Huns that threatened to overrun their original territory. They had no hostile intent, and first simply sought refuge in the Roman empire, but when that was not readily granted, they resorted to violence. Later, they fled to Spain, where they instituted a not very effective kingship. Not very effective, because they could not halt the Islamic invasion from the south. After the Visigoths came the Ostrogoths, who had been occupied by the Huns. They, invaded the Roman empire, where they sought to install their own kingship.