The Huns
The Huns were a nomadic pastoral people from Mongolia eastern Asia who invaded Europe circa 370 A.D, and created an enormous empire centered in Germany. They were possibly the descendants of the Xiongnu, a northern people who were frequently at war with the Shang of China. Note, the Turkic, so-called "White Huns" (Hephthalites) had no direct connection with the Huns, these were White tribes who deliberately called themselves Huns, in order to frighten their enemies.
Attila
The historian Priscus (circa 450 A.D.) was a Greek-speaking Roman citizen who often meant with Attila, he described Attila’s personal features in his works, which are now mostly lost. Jordanes was a 6th century Roman bureaucrat who turned his hand to history later in life, he quotes Priscus thusly: When Attila's brother Bleda who ruled over a great part of the Huns had been slain by Attila's treachery, the latter united all the people under his own rule. Gathering also a host of the other tribes which he then held under his sway he sought to subdue the foremost nations of the world---the Romans and Visigoths. His army is said to have numbered 500,000 men. He was a man born into the world to shake the nations, the scourge of all lands, who in some way terrified all mankind by the dreadful rumors noised abroad concerning him. He was haughty in his walk, rolling his eyes here and there, so that the power of his proud spirit appeared in the movement of his body. He was indeed a lover of war, yet restrained in action, mighty in counsel, gracious to suppliants and lenient to those who were once received into his protection. He was short of stature, with a broad chest and a large head: his eyes were small, his beard thin and sprinkled with gray: and he had a flat nose and a swarthy complexion showing the evidences of his origin..
During Atila's reign he was one of the most feared enemies of both the Western and Eastern Roman Empires. He crossed the Danube twice and plundered the Balkans. The Huns invaded the Sassanid Persian Empire. When defeated in Armenia by the Sassanians, the Huns abandoned their invasion and turned their attentions back 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 treaty.
Crossing the Danube, they laid waste to the cities of Illyricum and forts on the river, including (according to Priscus) Viminacium, a city of Moesia. Their advance began at Margus, where they demanded that the Romans turn over a bishop who had retained property that Attila regarded as his. While the Romans discussed turning the Bishop over, he slipped away secretly to the Huns and betrayed the city to them.
While the Huns attacked city-states along the Danube, the Albino Vandals led by Geiseric captured the Western Roman province of Africa and its capital of Carthage. Carthage was the richest province of the Western Empire and a main source of food for Rome. The Romans stripped the Balkans area of forces to use them to defeat the Vandals in Africa, which left Attila a clear path through Illyricum into the Balkans, which they invaded in 441. The Hunnish army sacked Margus and Viminacium, and then took Singidunum (modern Belgrade) and Sirmium. During 442 Theodosius recalled his troops from Sicily and ordered a large issue of new coins to finance operations against the Huns. Believing he could defeat the Huns, he refused Atila's demands.
Attila responded with a campaign in 443. Striking along the Danube, the Huns, equipped with new military weapons like the battering rams and rolling siege towers, overran the military centres of Ratiara and successfully besieged Naissus (modern Niš). Advancing along the Nisava River, the Huns next took Serdica, Philippopolis, and Arcadiopolis. They encountered and destroyed a Roman army outside Constantinople but were stopped by the double walls of the Eastern Roman capital (Constantinople - Byzantium). They defeated a second army near Callipolis (modern Gallipoli). Theodosius, stripped of his armed forces, admitted defeat, sending the Magister militum per Orientem Anatolius to negotiate peace terms. The terms were harsher than the previous treaty: the Emperor agreed to hand over 6,000 Roman pounds (ca. 2000 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. 700 kg) in gold; and the ransom for each Roman prisoner rose to 12 solidi.
In 450, Attila proclaimed his intent to attack the Visigoth kingdom of Toulouse by making an alliance with Emperor Valentinian III. He had previously been on good terms with the Western Roman Empire and its influential general Flavius Aëtius. Aëtius had spent a brief exile among the Huns in 433, and the troops Attila provided him against the Goths and Bagaudae had helped earn him the largely honorary title of magister militum in the west. The gifts and diplomatic efforts of Geiseric, who opposed and feared the Visigoths, may also have influenced Attila's plans. However, Emperor Valentinian's sister was Honoria, who, in order to escape her forced betrothal to a Roman senator, had sent Atila 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 his sister Honoria. He also wrote to Attila strenuously denying the legitimacy of the supposed marriage proposal. Attila 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 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 half a million strong. 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 Orléans 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 Châlons, whose outcome is commonly considered to be a strategic victory for the Visigothic-Roman alliance. The Albino king Theodoric was killed in the fighting and Aëtius failed to press his advantage, because he feared the consequences of an overwhelming Visigothic 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 and starvation may have broken out in Attila's camp, thus helping to stop his invasion.
Emperor Valentinian III sent three envoys, the high civilian officers Gennadius Avienus and Trigetius, as well as the Bishop of Rome Leo I, who 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. 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 stopped. (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).
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 she was Albino) 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 dilated veins in the lower part of the esophagus rupture leading to death by hemorrhage.
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 they 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, buried the coffin under the riverbed, and then were killed to keep the exact location a secret.