When Rome could still resist
By the mid-5th century, the Western Roman Empire was going through a stage of enormous weakness. For centuries, Rome had dominated much of Europe, North Africa, and the lands surrounding the Mediterranean, but by then its borders were under constant threat, and various Germanic peoples had settled within its former territories. It was in this scenario that one of the most feared figures of his time appeared: Attila, king of the Huns.
On September 20, 451, according to the traditional date, the Battle of the Catalaunian Plains took place in Gaul, a territory that corresponds approximately to modern-day France. Attila had entered there at the head of a powerful army and intended to expand his domains even further, so to stop him, the Roman general Aetius gathered a large coalition in which several peoples participated, among them the Visigoths.
The clash was enormous and ended up halting Attila's advance, so the Huns were unable to prevail and had to retreat. The battle also had a decisive episode for the Visigoths: their king, Theodoric I, died during the combat.
The result allowed Rome to contain that threat, but the victory hid a much more worrying reality: to defend its territories, Roman power needed to rely increasingly on peoples who had previously been its enemies; the Visigoths were no longer simply outside the Roman world: they were part of the forces fighting to defend it.
From allies of Rome to new rulers
After the Catalaunian Plains, the Western Roman Empire continued to lose strength; economic difficulties, internal struggles, and the loss of control over numerous territories progressively weakened imperial authority.
While Rome tried to survive, the Germanic peoples were consolidating their own powers, and among them, the Visigoths are an especially important example for the history of Spain, since after settling in various territories of Gaul, they gradually shifted their center of power toward Hispania, where they would eventually create a kingdom with its capital in Toledo.
The transformation was slow; in 451, it still made sense to gather Romans and Visigoths to defend the territory against Attila, but twenty-five years later, the political situation had changed to such an extent that the Western emperor barely retained real authority.
On September 4, 476, the Germanic military leader Odoacer deposed Romulus Augustulus, a young emperor ruling in Italy, although Odoacer did not take his place as the new Western emperor but instead sent the imperial insignia to Constantinople and ruled Italy on his own, recognizing the emperor of the Eastern Roman Empire.
Traditionally, this event is considered the end of the Western Roman Empire and one of the great boundaries between Antiquity and the Middle Ages.
The world that was born after Rome
Only twenty-five years passed between 451 and 476, but during that period the balance of power in Western Europe changed profoundly: at the Catalaunian Plains, Rome could still assemble an army alongside the Visigoths to stop Attila, but by 476, the Western Roman emperor had been removed from power and the former imperial territories were increasingly controlled by new kingdoms, while the Visigoths would occupy a prominent place on that new map. Their evolution is especially important for the history of Spain because they would end up establishing a kingdom in Hispania that would have Toledo as its capital and would dominate a large part of the peninsula during the following centuries.
The fall of 476 did not mean that Rome disappeared suddenly; many of its laws, cities, customs, administrative structures, and traditions continued for centuries, but what disappeared was the power of the Western Roman emperor as an effective authority over those territories, and thus a new stage began: Rome ceased to govern the West and the Germanic kingdoms began to take its place, among whom the Visigoths would end up becoming protagonists of one of the first great stages of the medieval history of Spain.
