By c.391 BC the city's overspill had overtaken the Aventine and the Campus Martius sufficiently to threaten its defences; around that year, a Gallic invasion overran and temporarily held the city.
By c.391 BC the city's overspill had overtaken the Aventine and the Campus Martius. This seems to have left the city vulnerable to attack; around that year, a Gallic invasion overran and temporarily held the city.