During the reign of Attila's uncle Rua, the Huns developed a complicated relationship with the two halves of the Roman Empire. On the one hand, Rua extracted tribute from the Eastern Roman Empire, centered at Constantinople. On the other, the Western Roman Empire, based in Rome itself, hired the Huns as mercenaries in its fight against the Vandals, Franks, and Burgundians.
425, Western Roman general Aetius hires Hunnic mercenaries
For the first time in 425, the government of Rome employed Huns as a mercenary army. By this time, Rome had very few actual Roman troops. Nearly all of its military power came from such agreements with "barbarian" peoples. Late 420s, Rua seizes control and eliminates other kings of the Huns
Prior to this time, the Huns had maintained a nomadic-style confederation in which each clan had a king. The group as a whole was then ruled by the highest king, but his power was checked by the other clan rulers. This structure makes sense for people who have to split up in order to find pasture lands for their animals, but in Europe the Huns no longer relied on their herds. With gold flowing in from the Romans, the Huns became a more settled people, and Attila's uncle Rua decided that the time was ripe to take all of the power into this own hands. He evidently executed the other, lesser kings. 430, Rua signs peace treaty with Eastern Roman Empire, exacts tribute
The Roman Empire had for centuries been accustomed to extracting tribute from its provinces. In 430, Rua turned that formula on its head. He made a peace treaty with the Eastern Roman Empire, based in Constantinople. In exchange for his promise not to attack the empire, Rua and the Huns would receive a yearly payment of 350 pounds of gold. 433, Western Roman Empire surrenders Pannonia to the Huns
As payment for military services rendered, the cash-starved Western Roman Empire ceded its province of Pannonia to the Huns in 433. Pannonia encompassed much of modern western Hungary, along with bits of neighboring countries. 433, Aetius takes de facto power over the Western Roman Empire
Attila's good friend Aetius seized the reins of power from the Emperor of the Western Empire in 433 (although the Emperor remained as a figurehead). This ensured further business for the Hunnic mercenaries. 434, Rua dies and his nephews Bleda and Attila take the throne
Bleda was the older brother, and thus probably had more power than Attila initially. It is nevertheless interesting that he was not able to exclude his young brother from the kingship, perhaps indicating some weakness in Bleda. 435, Aetius hires the Huns to fight the Vandals and Franks
The Western Roman Empire faced increasing pressure from the Vandals and Franks of Gaul, probably due to the accordion effect of the Hunnic move into Europe. Somewhat ironically, then, the Romans hired the Huns to fight the other restive barbarian groups. 435, Treaty of Margus under which Eastern Roman Empire's tribute doubles
In 435, an embassy from Constantinople approached Bleda and Attila at the city of Margus, in order to negotiate a new non-aggression pact with the leaders of the Huns. Being consummate horsemen, the two brothers chose to remain seated on their mounts during the negotiation, so the Romans were forced to stay on their horses as well. The saddle-sore Romans soon agreed to double their yearly tribute to the Huns, from 350 pounds of gold to 700 pounds. c. 435-438, Huns attack Sassanid Persia and are defeated in Armenia
For several years, the Huns essentially drop out of Roman records. This is because Bleda and Attila were engrossed in a fight against the Sassanid Empire of Persia. The Sassanids finally were able to inflict a heavy defeat on the Huns in present-day Armenia, thus fending them off. 436, Aetius and Huns destroy the Burgundians
Even while the main strength of the Hunnic army was busy in Persia, some mercenaries were fighting alongside the Western Romans. In 436 the defeated and virtually wiped out the Burgundians, driving them deep into what is now France.
