Following the collapse of the Roman Empire, what group of invading Barbarians, a Germanic race from the north, took power on the Iberian Peninsula? What is this group commonly called, even though composed of several different tribes?

Visigoth

Explanation: Visigoth was the name given to the western tribes of Goth. The Visigoths mounted a successful invasion of the Roman Empire , beginning in 376, and ultimately defeated them within the Battle of Adrianople in 378 A.D. The Visigoths were an early Germanic folks that in conjunction with the Ostrogoths (those within the east)constituted the 2 major branches of the Goths. These tribes prospered and spread throughout the late Roman Empire in Late Antiquity, due to the Migration Period.

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place.