ROMAN EMPIRE FALLS
Officials believe geographic size to be a leading cause
Geographic size: Difficulty of defense and administration
The old saying goes that "All roads lead to Rome" but is equally true that these roads led away from Rome. In order for the Empire to be an Empire, Rome had to exert control over the entirety of the territory, from the provinces nearest to the Eternal City itself, all the way to the German Frontier and Hadrian's Wall in England. Two important means of projecting and retaining this control over such a vast territory were the Roman form of government and the Roman army. Regarding the government, unfortunately, "Rome tried to control this vast empire with a government designed for a small city-state. Faced with governing the entire Mediterranean World, the system failed" (World History 175).
The defense system of the Roman Empire suffered from a similar problem of geographic extremes. Due to Rome's practice of expanding through military force, there were always opposing forces just beyond the borders on all sides. Germanic tribes, such as the Visigoths or Huns, who ended up invading large portions of the Empire, including Rome, in the 5th century CE were just the most powerful example. Rome had to station forces at its borders surrounding the whole Empire, which posed a problem of manpower and defenses. Two main tactics were employed, but both were costly. One, Rome build massive defensive fortifications at the frontier. See the image of Hadrian's Wall below that was built across the expanse of Britain at its border with Scotland. The second tactic was to enlist locals into the army. When the Roman economy began to fail, these now powerful local armies were able to turn on their imperial masters (cf. World History 175).
The Roman Forum
The glory that was Rome can still be seen in the ruins of the Forum in central Rome. Though most of the buildings have fallen (History.com photo)
Hadrian's Wall
Built in 122 CE, this massive fortification protected the Roman province of Britain from the warring tribes of Scotland. (History.com photo)
Extent of the Roman Empire
This map shows the Roman Empire at its height in the 2nd century CE. (Encyclopædia Britannica map)
The Roman Highway System
More war is better than no war at all
Bibliography
“Roman Leaders and Emperors.” 2012. The History Channel website. Dec 11 2012, 9:46 http://www.history.com/photos/roman-leaders-and-emperors.
Rome, ancient: Roman Empire, AD 117. Map. Encyclopædia Britannica Online. Web. 11 Dec. 2012.