The sack of Rome on 24 August 410 AD was undertaken by the Visigoths led by their king, Alaric. At that time, Rome was no longer the administrative capital of the Western Roman Empire, having been replaced first by Mediolanum (now Milan) in 286 and then by Ravenna in 402. Nevertheless, the city of Rome retained a paramount position as "the eternal city" and a spiritual center of the Empire. This was the first time in almost 800 years that Rome had fallen to a foreign enemy, and the sack was a major shock to contemporaries, friends and foes of the Empire alike.

The sacking of 410 is seen as a major landmark in the fall of the Western Roman Empire. St. Jerome, living in Bethlehem, wrote: "the city which had taken the whole world was itself taken".

The Germanic tribes had undergone massive technological, social, and economic changes after four centuries of contact with the Roman Empire. From the first to fourth centuries, their populations, economic production, and tribal confederations grew, and their ability to conduct warfare increased to the point of challenging Rome.

The Goths, one of the Germanic tribes, had invaded the Roman Empire on and off since 238. But in the late 4th century, the Huns began to invade the lands of the Germanic tribes, and pushed many of them into the Roman Empire with greater fervor. In 376, the Huns forced many Therving Goths led by Fritigern and Alavivus to seek refuge in the Eastern Roman Empire. Soon after, starvation, high taxes, hatred from the Roman population, and governmental corruption turned the Goths against the empire.

The Goths rebelled and began looting and pillaging throughout the eastern Balkans. A Roman army, led by the Eastern Roman emperor Valens, marched to put them down. At the Battle of Adrianople in 378, Fritigern decisively defeated emperor Valens, who was killed in battle. Peace was eventually established in 382 when the new Eastern emperor, Theodosius I, signed a treaty with the Thervings, who would become known as the Visigoths. The treaty made the Visigoths subjects of the empire as foederati. They were allotted the northern part of the dioceses of Dacia and Thrace, and while the land remained under Roman sovereignty and the Visigoths were expected to provide military service, they were considered autonomous.

Fritigern died around 382. Possibly in 391, a Gothic chieftain named Alaric was declared king by a group of Visigoths, though there is debate over the nature of his position and the year of his ascension (Jordanes says 400, Peter Heather says 395). He then led an invasion into Eastern Roman territory outside of the Goths' designated lands. Alaric was defeated by Theodosius and his general Flavius Stilicho in 392, who forced Alaric back into Roman vassalage.

In 394, Alaric led a force of Visigoths as part of Theodosius's Eastern Roman army to invade the Western Roman Empire. At the Battle of the Frigidus, around half the Visigoths present died fighting the Western Roman army led by the usurper Eugenius and his general Arbogast. Theodosius won the battle, and although Alaric was given the title comes for his bravery, tensions between the Goths and Romans grew as it seemed the Roman generals had sought to weaken the Goths by making them bear the brunt of the fighting. Alaric was also enraged he had not been granted a higher office in the imperial administration.

When Theodosius died on 10 January 395, the Visigoths considered their 382 treaty with Rome to have ended. Alaric quickly led his warriors back to their lands in Moesia, gathered most of the federated Goths in the Danubian provinces under his leadership, and rose in rebellion, invading Thrace and approaching the Eastern Roman capital of Constantinople. The Huns, at the same moment, invaded Asia Minor.