Complex sentence: Burgundian refugees fleeing the destruction of Worms by the Huns in 437 were resettled by the military commander of the west, Aëtius, at Lugdunum, which became the capital of the new Burgundian kingdom in 461.
Split into simpler sentences: Burgundian refugees fleeing the destruction of Worms by the Huns in 437 were resettled by the military commander of the west, Aëtius, at Lugdunum. This became the capital of the new Burgundian kingdom in 461.