Why did the Roman Empire fall?

In 476 CE the last western Roman emperor was deposed. But an empire that ruled the Mediterranean for centuries doesn't vanish overnight — so what actually brought Rome down?

Think of the empire as a structure under four loads at once. Politically, emperors were made and unmade by armies — the Crisis of the Third Century saw dozens of claimants in fifty years. Economically, debasing the silver coinage to pay those armies fed inflation. Militarily, a frontier thousands of kilometres long cost more than the tax base could bear, and the army increasingly hired the very peoples pressing on the border. Socially, plague and insecurity thinned the population that paid for it all.

Each strain was survivable alone; together they were not. 476 is best read as the date the scaffolding was taken away from a building already hollow.

Key sequence: the Crisis of the Third Century (235–284) nearly breaks the empire; Diocletian stabilises it partly by splitting administration; Constantine founds Constantinople (330), shifting weight eastward. The Goths' victory at Adrianople (378) shows the field army can be beaten; Rome itself is sacked in 410 (Visigoths) and 455 (Vandals); in 476 the general Odoacer deposes Romulus Augustulus and doesn't bother appointing a successor.

Historians weight the causes differently — Gibbon stressed internal decay, modern scholars stress fiscal-military overstretch and migration pressure — but the consensus is multi-causal decline, not a single knockout. Crucially, the eastern (Byzantine) empire, richer and easier to defend, survived until 1453: whatever 'fell' in 476, it wasn't Roman civilisation as a whole.

Follow one thread — the coinage. The denarius was ~95% silver in the 1st century; by the 260s the 'silver' coin was a bronze piece with a silver wash of under 5%. Soldiers demanded pay in kind or gold, taxes shifted to goods and labour, and long-distance trade contracted — a measurable spiral in which paying for the army undermined the economy that paid for the army.

• Giving one cause ('the barbarians did it', 'moral decay') — examiners reward the interaction of causes, and 'barbarian' groups were often settled inside the empire as soldiers and taxpayers long before 476.
• Writing that the Roman Empire ended in 476 — only the western half did; the eastern empire ran nearly another millennium.

• NCERT Class 11 History (Themes in World History), Theme 3 — An Empire Across Three Continents
• Britannica — The fall of the Western Roman Empire