Why did the Goths admitted in 376 sack Rome in 410?

The short answer

• The Huns and Roman choices. Peter Heather gives the Huns a central place in the explanation. Their advance compressed peoples against Roman frontiers within a generation, linking the pressures behind the crossings of 376 and 406 with Attila’s campaigns in Chapter 11. Other historians emphasize the empire’s internal condition: earlier governments had dealt with Cimbri, Marcomanni and Goths. These questions belong together. Rome did not create the pressure from the steppe, but its institutions and decisions helped determine the outcome when people reached its borders.
• The cost of Adrianople. The force lost at Adrianople had served as the eastern empire’s strategic reserve. The Republic could replace losses after Cannae from a citizen-militia base and its Italian allies; the late empire needed money and recruits to rebuild its army. The 382 treaty supplied Gothic soldiers in response to that shortage. Later losses of taxable land could make replacement still harder: less revenue meant fewer resources for troops, and concessions to armed groups could in turn reduce the revenue available. Chapter 11 follows this fiscal argument. The treaty answered a real need, even though later outcomes were not inevitable.
• Civil wars and frontiers. Theodosius marched the eastern army west against Roman usurpers in 388 and 394, drawing resources away from the Rhine and Danube. A rival could take an emperor’s throne, so the danger was immediate. The provinces bore part of the cost when frontier forces were weakened. Peoples crossed the Rhine in 406 after withdrawals; Stilicho’s defense of Italy also drew troops from Britain and Gaul, where Constantine III emerged as a usurper. Protecting a ruler against Roman competitors could leave the empire less able to defend its borders.
• The problem of integration. Rome had brought Gauls, Spaniards and Illyrians into its political and military life over centuries. Could it have accommodated the Goths in a comparable way? Alaric’s long pursuit of office suggests an opportunity, although any agreement would have needed both parties to sustain it. Hostile factions at court and religious differences—the Goths were Arian Christians—made accommodation harder. Attacks on federate families in 408 pushed soldiers toward Alaric, making the problem more urgent.

What it changed

The exposed West. The division of 395 left the east with Constantinople’s fortified approaches and a larger share of imperial revenues—roughly two-thirds by one estimate. The west had the long Rhine and upper Danube frontiers, Britain, and the vital grain and taxes of Africa. Losses in 406, 410 and 439 therefore fell on the government with less capacity to replace them. The loss of Africa in 439 made the disparity especially consequential. Chapter 11 follows the western balance sheet.

The meaning of 410. The court was safe in Ravenna when Rome was sacked. Alaric died within months and his Goths later moved toward Gaul, but the event’s meaning outlasted its immediate damage. Pagans blamed the abandonment of the old gods. Augustine answered that no earthly city was the City of God: the fate of a political order was distinct from Christians’ ultimate hopes. That distinction helped shape Latin Christian thinking about politics for centuries.

Britain after imperial rule. Around 410 imperial government withdrew from Britain without an immediately succeeding single conquering government. Towns, villas, coinage and literacy contracted especially severely as the institutions supporting them disappeared. Bryan Ward-Perkins draws on pottery and coin distribution to examine the material consequences. Britain gives Chapter 12 a case in which to ask what the words “fall” and “transformation” explain.