Historians have been theorizing about the causes of the fall of Rome ever since. The most famous theory was one put forth in Edward Gibbon’s multivolume work The History of the Decline and Fall of the Roman Empire (1776), which argued that the Christian Church was to blame. After Christianity became the official religion of the empire, the best and the brightest leaders became leaders of the church rather than leaders of the government or the military.
Another theory about the fall of Rome is that the aqueducts, which carried the water supply, were lined with lead, and so the Romans slowly went crazy. Some geologists believe that the eruption of Mount Vesuvius released so much ash into the air that it brought about great climactic changes, which ruined Roman agriculture and weakened the empire.
Stolen from today’s Writer’s Almanac.