Formerly a group of nomadic people living beyond the Volga river in separate tribes presumably without a general leader or king, the Huns were first united under a single king Rua by 432. In 434, Attila, the nephew of Rua, gained control over all Hun tribes together with his brother Bleda, whom he murdered in 445.
They invaded the Balkans in 441, when Roman armies were busy with Vandals and Persians. After a short period of peace, Attila captured Gaul with an army reputed to be half a million, but was defeated by Aetius at Battle of Chalons. Attila then turned back and began to invade Italy in 452. He withdrew from capturing Rome possibly because of shortage of goods and a pestilence, though according to tradition because he was awed by a meeting with Pope Leo I the Great.
He died after a nasal hemorrhage and his empire was divided among his sons. After his death, he went on living as a legendary figure, and the character of Etzel in the Nibelungenlied (or Atli in the Volsunga Saga) possibly represents Attila.
"Attila" and "Ildikó" (Ildikó was the wife Attila married just before he died) are still popular names in Hungary.