Originating in Central and Inner Asia, the Avars arrived in the Carpathian Basin in 567/568. The first people to unite the whole of the Carpathian Basin under a single political authority, they established an empire which lasted approximately 250 years, until the early 8th century. In its early period, Avar culture bore the marks of many different cultures: Byzantine, East European and West European alike. The extraordinarily uniform ‘late Avar culture’ which developed in the 8th century was first and foremost a Carpathian Basin phenomenon.

Interesting facts:

It was the Avars who brought the stirrup to Europe. By using stirrups, a rider was better able to stay on his horse; also, he could stand up and could shoot arrows while riding. 
During the winter of 558–559 in Constantinople, ‘the whole city was amazed, because it had never before seen people’ like the Avars.