In much of Western Europe, he is remembered as the epitome of cruelty and rapacity. In contrast, some histories and Chronicles lionize him as a great and noble king, and he plays major roles in three Norse sagas.
Their united power appeared or began to form in Europe in the 400s. They achieved military superiority over their neighbours by their readiness for battle, unusual mobility, and weapons, including the composite bow.
The death of Rugila (also known as Rua or Ruga) in 434 left his nephews Attila Dragomer and Bleda (also known as Buda), the sons of his brother Mundzuk, in control over all the united Hun tribes. At the time of their accession, the Huns were bargaining with Byzantine emperor Theodosius II's envoys over the return of several renegades (possibly Hunnic nobles not in agreement with the brothers' leadership) who had taken refuge within the Byzantine Empire. The following year Attila and Bleda met with the imperial legation at Margus (present-day Požarevac) and, all seated on horseback in the Hunnic manner, negotiated a successful treaty: the Romans agreed not only to return the fugitives, but also to double their previous tribute of 350 Roman pounds (ca. 114.5 kg) of gold, open their markets to Hunnish traders, and pay a ransom of eight solidi for each Roman taken prisoner by the Huns. The Huns, satisfied with the treaty, decamped from the empire and returned to their home in the Hungarian Great Plain, perhaps to consolidate and strengthen their empire. Theodosius used this opportunity to strengthen the walls of Constantinople, building the city's first sea wall, and to build up his border defences along the Danube.
The Huns remained out of Roman sight for the next few years as a Hunnic force invaded the Persian Empire. A defeat in Armenia by the Sassanid Persians caused them to abandon this attempt and return their attentions to Europe. In 440 they reappeared in force on the borders of the Roman Empire, attacking the merchants at the market on the north bank of the Danube that had been established by the treaty. Crossing the Danube they laid waste to Illyrian cities and forts on the river, among them, according to Priscus, Viminacium, which was a city of the Moesians in Illyria. Their advance began at Margus, for when the Romans discussed handing over the offending bishop, he slipped away secretly to the Huns and betrayed the city to them.
As Theodosius had conquered the river's defences, the Vandals, under the leadership of Geiseric, captured the Western Roman province of Africa with its capital of Carthage in 440 and the Sassanid Shah Yazdegerd II invaded Armenia in 441. Stripping the Balkan defenses of forces requested by the West Romans, in order to launch an attack on the Vandals in Africa (which was the richest province of the Western empire and a main source of the food supply of Rome) left Attila and Bleda a clear path through Illyria into the Balkans, which they invaded in 441. The Hunnish army, having sacked Margus and Viminacium, took Singidunum (modern Belgrade) and Sirmium before halting. A lull followed in 442 and during this time Theodosius recalled his troops from Sicily and ordered a large new issue of coins to finance operations against the Huns. Having made these preparations, he thought it safe to refuse the Hunnish kings' demands.
Attila responded with a campaign in 443. Striking along the Danube, the Huns overran the military centres of Ratiara and successfully besieged Naissus (modern Niš) with battering rams and rolling towers—military sophistication that was new to the Hun repertoire—then pushing along the Nisava they took Serdica (Sofia), Philippopolis (Plovdiv), and Arcadiopolis. They encountered and destroyed the Roman army outside Constantinople and were stopped by the double walls of the Eastern capital. A second army was defeated near Callipolis (modern Gallipoli) and Theodosius, now without any armed forces to respond, admitting defeat, sent the court official Anatolius to negotiate peace terms, which were harsher than the previous treaty: the Emperor agreed to hand over 6,000 Roman pounds (ca. 1,963 kg) of gold as punishment for having disobeyed the terms of the treaty during the invasion; the yearly tribute was tripled, rising to 2,100 Roman pounds (ca. 687 kg) in gold; and the ransom for each Roman prisoner rose to 12 solidi.
Their demands met for a time, the Hun kings withdrew into the interior of their empire. According to Jordanes (following Priscus), sometime during the peace following the Huns' withdrawal from Byzantium (probably around 445), Bleda died (killed by his brother, according to the classical sources), and Attila took the throne for himself.
In 447 Attila again rode south into the empire through Moesia. The Roman army under the Gothic magister militum Arnegisclus met him in the Battle of the Utus and was defeated, though not without inflicting heavy losses. The Huns were left unopposed and rampaged through the Balkans as far as Thermopylae. Constantinople itself was saved by the intervention of the prefect Flavius Constantinus who organized the reconstruction of the walls that had been previously damaged by earthquakes, and, in some places, to construct a new line of fortification in front of the old. An account of this invasion survives:
However Valentinian's sister was Honoria, who, in order to escape her forced betrothal to a Roman senator, had sent the Hunnish king a plea for help – and her engagement ring – in the spring of 450. Though Honoria may not have intended a proposal of marriage, Attila chose to interpret her message as such. He accepted, asking for half of the western Empire as dowry. When Valentinian discovered the plan, only the influence of his mother Galla Placidia convinced him to exile, rather than kill, Honoria. He also wrote to Attila strenuously denying the legitimacy of the supposed marriage proposal. Attila, not convinced, sent an emissary to Ravenna to proclaim that Honoria was innocent, that the proposal had been legitimate, and that he would come to claim what was rightfully his.
Attila also interfered in a succession struggle after the death of a Frankish ruler. Attila supported the elder son, while Aëtius supported the younger.
Attila gathered his vassals—Gepids, Ostrogoths, Rugians, Scirians, Heruls, Thuringians, Alans, Burgundians, among others and began his march west. In 451 he arrived in Belgica with an army exaggerated by Jordanes to half a million strong. J.B. Bury believes that Attila's intent, by the time he marched west, was to extend his kingdom – already the strongest on the continent – across Gaul to the Atlantic Ocean.
On April 7, he captured Metz. Other cities attacked can be determined by the hagiographic vitae written to commemorate their bishops: Nicasius was slaughtered before the altar of his church in Rheims; Servatus is alleged to have saved Tongeren with his prayers, as Saint Genevieve is to have saved Paris. Lupus, bishop of Troyes, is also credited with saving his city by meeting Attila in person.
Aëtius moved to oppose Attila, gathering troops from among the Franks, the Burgundians, and the Celts. A mission by Avitus, and Attila's continued westward advance, convinced the Visigoth king Theodoric I (Theodorid) to ally with the Romans. The combined armies reached Orleans ahead of Attila, thus checking and turning back the Hunnish advance. Aëtius gave chase and caught the Huns at a place usually assumed to be near Catalaunum (modern Châlons-en-Champagne). The two armies clashed in the Battle of Chalons, whose outcome is commonly considered to be a Pyrrhic victory for the Visigothic-Roman alliance. Theodoric was killed in the fighting and Aëtius failed to press his advantage, according to Edward Gibbon and Edward Creasy because he feared the consequences of an overwhelming Visogothic triumph as much as he did a defeat. From Aëtius' point of view, the best outcome was what occurred: Theodoric died, Attila was in retreat and disarray, and the Romans had the benefit of appearing victorious.
Attila returned in 452 to claim his marriage to Honoria anew, invading and ravaging Italy along the way. The city of Venice was founded as a result of these attacks when the residents fled to small islands in the Venetian Lagoon. His army sacked numerous cities and razed Aquileia completely, leaving no trace of it behind. Legend has it he built a castle on top of a hill north of Aquileia to watch the city burn, thus founding the town of Udine, where the castle can still be found. Aëtius, who lacked the strength to offer battle, managed to harass and slow Attila's advance with only a shadow force. Attila finally halted at the River Po. By this point disease may have broken out in Attila's camp, thus helping to stop his invasion.
At the wish of Emperor Valentinian III, Pope Leo I, accompanied by the Consul Avienus and the Prefect Trigetius, met Attila at Mincio in the vicinity of Mantua, and obtained from him the promise that he would withdraw from Italy and negotiate peace with the emperor. Prosper of Aquitaine gives a short, reliable description of the historic meeting. The later anonymous account, a pious "fable which has been represented by the pencil of Raphael and the chisel of Algardi" (as Gibbon called it) says that the Pope, aided by Saint Peter and Saint Paul, convinced him to turn away from the city, promising Attila that if he left in peace, one of his successors would receive a holy crown. Priscus reports that superstitious fear of the fate of Alaric—who died shortly after sacking Rome in 410—gave him pause.
After Attila left Italy and returned to his palace across the Danube, he planned to strike at Constantinople again and reclaim the tribute which Marcian had cut off. (Marcian was the successor of Theodosius and had ceased paying tribute in late 450 while Attila was occupied in the west; multiple invasions by the Huns and others had left the Balkans with little to plunder.) However Attila died in the early months of 453. The conventional account, from Priscus, says that at a feast celebrating his latest marriage to the beautiful and young Ildico (if uncorrupted, the name suggests a Gothic origin) he suffered a severe nosebleed and choked to death in a stupor. An alternative theory is that he succumbed to internal bleeding after heavy drinking or a condition called esophageal varices, where a hemorrhoid in the lower part of the esophagus ruptures leaving the person to choke on his/her own blood.
Another account of his death, first recorded 80 years after the events by the Roman chronicler Count Marcellinus, reports that "Attila, King of the Huns and ravager of the provinces of Europe, was pierced by the hand and blade of his wife. The Volsunga saga and the Poetic Edda also claim that King Atli (Attila) died at the hands of his wife, Gudrun. Most scholars reject these accounts as no more than hear-say, preferring instead the account given by Attila's contemporary Priscus. Priscus' version, however, has recently come under renewed scrutiny by Michael A. Babcock. Based on detailed philological analysis, Babcock concludes that the account of natural death, given by Priscus, was an ecclesiastical "cover story" and that Emperor Marcian (who ruled the Eastern Roman Empire from 450-457) was the political force behind Attila's death.
Jordanes says, "the greatest of all warriors should be mourned with no feminine lamentations and with no tears, but with the blood of men." His horsemen galloped in circles around the silken tent where Attila lay in state, singing in his dirge, according to Cassiodorus and Jordanes, "Who can rate this as death, when none believes it calls for vengeance?" then celebrated a strava (lamentation) over his burial place with great feasting. Legend says that he was laid to rest in a triple coffin made of gold, silver, and iron, along with some of the spoils of his conquests. His men diverted a section of the river Tisza, buried the coffin under the riverbed, and then were killed to keep the exact location a secret.
His sons Ellac (his appointed successor), Dengizich, and Ernakh fought over the division of his legacy, specifically which vassal kings would belong to which brother. As a consequence they were divided, defeated and scattered the following year in the Battle of Nedao by the Ostrogoths and the Gepids under Ardaric. According to Jordanes, Ardaric, who was once Attila's most prized chieftain, turned against the feuding brothers when he felt that they were treating the nations they ruled as slaves.
Attila's many children and relatives are known by name and some even by deeds, but soon valid genealogical sources all but dry up and there seems to be no verifiable way to trace Attila's descendants. This hasn't stopped many genealogists from attempting to reconstruct a valid line of descent for various medieval rulers. One of the most credible claims has been that of the tsars of Bulgaria (see Nominalia of the Bulgarian khans). A popular, but ultimately unconfirmed attempt tries to relate Attila to Charlemagne (see Attila the Hun to Charlemagne).
Attila is known in Western history and tradition as the grim flagellum dei (Latin: "Scourge of God"), and his name has become a byword for cruelty and barbarism. Some of this may have arisen from confusion between him and later steppe warlords such as Genghis Khan and Tamerlane. All are considered to be cruel, clever, and blood-thirsty lovers of battle and pillage. The reality of his character is probably more complex. The Huns of Attila's era had been mingling with Roman civilisation for some time, largely through the Germanic foederati of the border, so that by the time of Theodosius's embassy in 448 Priscus could identify two primary languages among the Huns, Gothic and Hunnic, with some people knowing Latin and Greek. Priscus also recounts his meeting with an eastern Roman captive who had so fully assimilated into the Huns' way of life that he had no desire to return to his former country, and the Byzantine historian's description of Attila's humility and simplicity is unambiguous in its admiration.
The origin of Attila's name is not known with confidence, because very little is known about Hunnic names. In the Hunnic language Danube-Bulgarian, the etymology "oceanic (universal) [ruler]" has been proposed. Also the word possibly originates from Turkic Atyl/Atal/Atil/Itil meaning water, river (also, ancient name of Volga river) with adjective suffix -ly. (Compare also Turkic medieval notable title atalyk - "senior as father"). This is correlating to the fact that the Polish Chronicle is using Attila's name as Aquila bearing the Latin aqua inside. Others believe that the name may have connection to Hungarian Ítélet meaning judgement or Old-Turkic via the loandword in Gothic (or Gepid) atta ("father") and the diminutive suffix -ila. Attila was not a rare name in Central Europe prior to Attila making his mark on history; the historical record shows numerous persons with the name preceding him. 'Attila' has many variants: Atli and Atle in Norse, Ætla, Attle and Atlee in English, Attila/Atilla/Etele in Hungarian (all the three name variants are used in Hungary; Attila is the most popular variant), Etzel in modern German or Attila, Atila or Atilla in modern Turkish.
Attila has been portrayed in various ways, sometimes as a noble ruler, sometimes as a cruel barbarian.
Set in the final days of the Roman Empire, Dietrich's fifth novel follows the attempt of Attila the Hun to conquer the West.