The Battle of Chalons was fought during the Hunnic Invasions of Gaul.
Battle of Chalons Summary:
In the years preceding 450, Roman control over Gaul and its other outlying provinces had grown weak. That year, Honoria, the sister, of Emperor Valentinian III, offered her hand in marriage to Attila the Hun with the promise that she would deliver half the Western Roman Empire as her dowry. Long a thorn in her brother's side, Honoria had earlier been married to Senator Herculanus in an effort to minimize her scheming. Accepting Honoria's offer, Attila demanded that Valentinian deliver her to him. This was promptly refused and Attila began preparing for war.
Attila's war planning was also encouraged by the Vandal king Gaiseric who wished to wage war on the Visigoths.
Forced to abandon the attack or be trapped in the city, Attila began retreating northeast in search of favourable terrain to make a stand.
Reaching the Catalaunian Fields, he halted, turned, and prepared to give battle. On June 19, as the Romans approached, a group of Attila's Gepids fought a large skirmish with some of Aetius' Franks. Despite foreboding predictions from his seers, Attila gave the order to form for battle the next day. Moving from their fortified camp, they marched towards a ridge that crossed the fields.
Taking the top of the ridge, they repulsed Attila's assault and sent his men reeling back in disorder. Seeing an opportunity, Theodoric's Visigoths surged forward attacking the retreating Hunnic forces. As he struggled to reorganize his men, Attila's own household unit was attacked forcing him to fall back to his fortified camp. Pursuing, Aetius' men compelled the rest of the Hunnic forces to follow their leader, though Theodoric was killed in the fighting. With Theodoric dead, his son, Thorismund, assumed command of the Visigoths. With nightfall the fighting ended.
The next morning, Attila prepared for the expected Roman attack. In the Roman camp, Thorismund advocated assaulting the Huns, but was dissuaded by Aetius. Realizing that Attila had been defeated and his advance stopped, Aetius began to assess the political situation. He realized that if the Huns were completely destroyed, that the Visigoths would likely end their alliance with Rome and would become a threat. To prevent this, he suggested that Thorismund immediately return to the Visigoth capital at Tolosa to claim his father's throne before one of his brothers seized it. Thorismund agreed and departed with his men. Aetius used similar tactics to dismiss his other Frankish allies before withdrawaling with his Roman troops. Initially believing the Roman withdrawal to be a ruse, Attila waited several days before breaking camp and retreating back across the Rhine.
We didn't quite match that, but a rough guesstimate is around 5000 figures in total!