This was the first time in almost 800 years that Rome had fallen to an enemy. The previous sack of Rome had been accomplished by the Gauls under their leader Brennus in 387 BC. The sacking of 410 is seen as a major landmark in the decline and fall of the Western Roman Empire. St. Jerome, living in Bethlehem at the time, wrote that "The City which had taken the whole world was itself taken." These sackings of the city astonished all the Roman world. In any case, the damage caused by the sackings may have been overestimated. The population already started to decline from the late 4th century onward, although around the middle of the fifth century it seems that Rome continued to be the most populous city of the two parts of the Empire, with a population of not less than 650,000 inhabitants.