King of the Visigoths (417-451)
Theodoric I of the Visigoths (born about 395, died 451) was one of the longest-reigned of the Visigothic kings. His reign saw the kingdom expand into Spain and ended with his heroic death in one of history's great battles.
He became king two years after his father Wallia had established his people in the Aquitaine region of what is now southwestern France. Theodoric (no relation to the Ostrogothic king of a half-century later) eventually pushed southward into the Iberian peninsula and had gained control of approximately half of it by the time he died. Along the way, the Visigoths fought victorious wars with the Romans, the Suebi and the Vandals, the last of whom they compelled to leave Spain in 429.
In 451, the Hunnic King Attila (Attila the Hun in modern nomenclature, though Attila is not his real name--it's the name his subject Ostrogoths gave him) invaded Roman Gaul and made it clear that he had no intention of stopping there unless he was made to. This was a direct threat to Theodoric's kingdom, so the King responded to a call from the Roman general Aetius to help the Romans fight Attila and his fearsome army. That summer, Attila reached Orleans before Aetius relieved the Huns' siege of that place. Attila then withdrew into Champagne to choose a battleground, while Theodoric and Aetius joined forces. In late summer, the two sides met near the modern city of Chalons--the Romans, Franks and Visigoths against the Huns and Ostrogoths, forced by defeat into fighting for Attila.
In the early afternoon, the Huns turned their full force on the Visigoths. The brave king was killed in battle while rallying his men to meet the threat. His son Thorismund was now King of the Visigoths in his father's stead, but that wouldn't mean much unless his men stopped the Huns. He personally led them back into the battle to avenge their fallen leader, and drove the Huns back. When Aetius' Romans and Franks did the same on the other flank, the battle was won. Attila retreated to the east and never returned to Gaul. Two years later he died, and the Ostrogoths revolted, regaining their independence.