jan 1, 401 - The sack of Rome by the Visigoths
The huns attack and push the Visigoths into Rome and so the Visigoths attack Rome. Under Alaric the visigoth sack Rome. It was a less brutal sack and the visigoth were respectful to Christian monuments as they themselves were Christian too. Although Rome was looted, it's precious monuments were left majority untouched.
Added to timeline:
Timeline of Ancient Rome
Timeline for Mr. Chapman