The Goths were a Germanic tribe who played an important role in the fall of the Roman Empire in the West. They had been periodic invaders for centuries but in the 370's AD they were forced under pressure from the Huns to migrate into the Roman Empire.
The Goths were treated so badly by the Roman officials (stories saying they had to sell their children as slaves for dog meat) that under their warlord Fritigern they rebelled (378 AD) decisively defeating the Eastern Romans at the battle of Adrianople killing the Emperor Valens in the process.
For the first time the Romans had to accept an independent people living within their borders. And for a time the Goths lived peacefully within the Empire some even joining the Roman army in their fight against the Huns. But on the death of Emperor Theodosius in 395 they again rose in rebellion under their leader (and former Roman general) Alaric.
Sack of Rome
The Goths lay siege to Rome three times finally sacking her in 410 AD. By all accounts it was a gentle sacking by the standards of the day. Very few buildings were burn't or people killed. It has to be remembered this was a Roman Army (albeit a barbarian one) and they were not out to destroy Rome or her empire. The Goths were seeking a homeland of their own within the Empire. Alaric's successors led their people out of Italy and and after the defeat of the Huns at the battle of Battle of the Catalaunian Plains (451 AD) set up an independent powerful kingdom in Aquitaine within the Roman empire. This greatly weakened Rome and the Empire in the West would be gone within 25 years falling in 476 AD
In the year 507 the Goths in Gaul were defeated by the Franks and were forced beyond the Pyrenees. For 200 years their kingdom in Spain flourished. In 711, when the Moors crossed to Spain from Africa, the Visigothic kingdom was destroyed.