Little is known of the early life of Attila before the death of his uncle Rua, who had led a loose confederation of Hunnic tribes north of the Danube River on various short-lived military campaigns. Attila and his brother Bleda took control of the Huns, sharing a dual kingship following Rua's death in 434. Following in the footsteps of their uncle, the two kings initially launched attacks against the Eastern Roman Empire (Byzantium) in hopes of generating a steady income of tribute. Unfortunately for both sides, the Romans often failed to keep their word, delivering little tribute and thus incurring swift and brutal reprisals from the Hunnic raiders. The saving grace for the Byzantines may have been Attila's western ambitions, where the Hunnic army occupied itself with fresh conflicts.
The mysterious death of his brother Bleda in 445, some say by Attila's own hand, left Attila as the sole leader of an increasingly unified Hunnic force. In 447, Attila once again led his army into battle against the legions of the Eastern Roman Empire at the Battle of Utus, successfully defeating the Roman force, leaving little remaining opposition. However, Attila's army suffered substantial casualties during the battle, which prevented him from seizing the Eastern Roman capital, Constantinople. Instead, Attila struck northward towards the Balkans (also Eastern Roman territory), sacking city after uncontested city, plundering everything his men could carry.
After sweeping through the Eastern Roman Empire, Attila set his sights to the west. Moving swiftly across Europe, he launched successful attacks against the Visigoths throughout Gaul in 451-452. As the Hunnic horde marched onwards, many of the various tribal people they encountered joined Attila's force, some by choice, others compelled by intimidation. Regardless, the Huns were bolstered by these new recruits, and continued to pillage their way through the region until encountering a united Visigoth-Roman force on the fields of Gaul. At The Battle of the Catalaunian Plains, Attila was turned back by the Roman-led force, the only major defeat in his lifetime, providing Rome and her allies a temporary reprieve.
It is said that the sister of Roman Emperor Valentinian III, Honoria, who had secretly plotted to murder her timid brother and seize his throne, was exiled from Rome and sent to a convent in Constantinople. During this exile, Valentinian promised his sister's hand in marriage to an unknown Roman senator. Upon learning of her betrothal, Honoria attempted to contact Attila and gain his assistance in escaping the marriage. For reasons unknown, she sent Attila her engagement ring, which Attila interpreted as a marriage proposal. Claiming half of the Western Roman Empire as his dowry, Attila moved his force to invade Italy, despite Valentinian's insistence that the proposal was invalid.
After years of clashes with the Romans, Attila finally marched on their homeland of Italy in 452. After sacking a number of cities in the northern reaches, Attila received numerous envoys from Valentinian, including Pope Leo I, all of whom pleaded with Attila to leave Italy without pursuing Rome further. For reasons that are unclear, Attila obliged (most likely due to lack of supplies). Shortly thereafter in 453, Attila died mysteriously. Some scarce evidence suggests that it may have been a simple nosebleed that toppled the mighty Hun on the night of his wedding, while other equally questionable accounts suggest he may have been assassinated.
The Roman historian Jordanes wrote that Attila's men cut their hair and slashed themselves with swords to honor Attila in death, stating "The greatest of all warriors should be mourned with no feminine lamentations and with no tears, but with the blood of men."