After several generations of Roman superiority and arrogance, Visigothic mercenaries entered Rome on August 24, 410 ce, and reminded their erstwhile masters of where the real military power lay. Alaric, leader of the Visigoths, had been left embittered by the experience at the Battle of Frigidus. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.