Attila was not Mr. Nice Guy, but as horse-barbarian conquerors go he wasn't so bad. He didn't level any cities and divert rivers over the ruins, or make pyramids of skulls, or impale thousands of people on wooden stakes, or nail their hats to their heads. All he did was murder brothers and cousins to secure his inheritance, kill lots of people in battle, take slaves, loot and plunder and lay waste, and the like; perfectly acceptable and civilized behavior for centuries among the ruling Romans (and Greeks, Persians, and Chinese.) Besides clinging to his barbarian ways, he remained stubbornly pagan. Rome was properly (Roman) Catholic by then, giving Romans another reason to look down on the barbarians (all non-Romans except for the better classes of Greeks). Some or most of the Germans were Christians by now, although mostly “heretical” Christians who followed the theology of Arius, and didn't follow the orders of the Pope and, worse, didn't pay tithes to the Bishop of Rome and taxes to Rome's emperors.
Since most of the history we have from this time and place was written by Catholic monks, Attila gets some very bad press for dissing his Pope and stealing the plate from various churches, cathedrals and monasteries. This is why the Almighty struck him down, although passing out from too much wine and drowning from a nosebleed also had something to do with it, if that's how he really died—he may still have at least one living relative who wanted to be king.
Attila's biggest battle was at Châlons on June 20, 451, which I often see listed as one of the decisive battles of history. Well, it was big for its time and place, and it was probably interesting in a military sense, but monks aren't generally interested in military stuff, so they didn't write down much useful detail. Attila had a big army, mostly warriors from subject tribes and most of them German. Both a large Roman army under Flavius Aetieus (made up largely of German legionnaires and auxiliaries) and a large army of non-Romanized Germans under Theodoric I, king of the Visigoths, were fighting against Attila. According to the monks, the Christian coalition won.
Atilla invaded Italy the next year, possibly because he thought Gaul was looted out for the present, but Aetius decided to solved Hun problem in much the same way the US Army handled the Souix, Comanche, and Apache problems. Instead of chasing the after the warriors, Aetius hit the Huns at home, slaughtering or enslaving the women and children and old men. Atilla pulled out of Italy back to what remained of his people, and died the next year before launching a new campaign. Then his makeshift empire melted away like snow on a hot stove.
I don't think Attila matters much, historically speaking. He's interesting, but he was just one charismatic and competent leader from a tough but small tribe who saw his opportunities and took them. We're not even sure what modern languages Hunnish might be most closely related to. The language is not only dead; it is forgotten; we have only a few words written down by unfriendly foreigners, and they have to be distorted. It would have been much the same if Attila had made himself a Roman Emperor, even if he had founded a dynasty, his grandchildren would have been speaking the Latin or Greek the locals spoke, and his people would have melted away into more sophisticated foreign cultures and larger foreign populations, exactly as they did in the history they got.
About half of China's dynasties have begun as barbarian conquerors; “Barbarians may enter the Middle Kingdom, but they are not permitted to leave.” That is a cryptic way of saying China is never really conquered because any conquerors quickly become Chinese. Rome had a similar power to integrate both conquered and conquerors. The German Franks were soon speaking the local Latin dialect, which discovered itself to be French in a few more centuries; the German Visigoths and the German Vandals who conquered Iberia began speaking the local Latin dialects, which became Spanish and Portuguese. Attillus Augustus Imperator would have just made for more modern-day Attilas, Attillos, and, possibly, Adelles--and Edsels.
The Edsel, named after Henry Ford's only legitimate son, might as well have been named the Attila because “Edsel” is one of the Germanic versions of the name, which had somehow become traditional in at least one family of Fords, perhaps another Viking legacy to the Irish to go along with Dublin and trial by jury. Ford should have gone for the original version, both for the car and the son—although Henry Ford was much more of an Attila than Edsel. Maybe the man who put America on gasoline-driven wheels was more of an Attila than Attila. Hitler kept a bust of Henry Ford in his office.
I'm in love, I'm in love,
With Attila the Hun,
Attila the Hun,
Attila the Hun.
Though he pillaged my village
And killed everyone,
I'm in love with Attila the Hun.
--Lyrics of a silly song I heard on the Dick Van Dyke Show as a kid, at least the way I remember it.