The Eurasian nomads were a large group of nomadic peoples from the Eurasian Steppe, who often appear in history as invaders of Europe, Western Asia, Central Asia, Eastern Asia, and South Asia. A nomad is a member of people having no permanent abode, who travel from place to place to find fresh pasture for their livestock. The generic title encompasses the varied ethnic groups who have at times inhabited the steppes of Central Asia, Mongolia and what is now Russia and Ukraine. They domesticated the horse around 3500 BCE, vastly increasing the possibilities of nomadic life and subsequently their economy and culture emphasised horse breeding, horse riding and nomadic pastoralism; this usually involved trading with settled peoples around the steppe edges. They developed the chariot, wagon, cavalry and horse archery and introduced innovations such as the bridle, bit and stirrup and the very rapid rate at which innovations crossed the steppelands spread these widely, to be copied by settled peoples bordering the steppes. During the Iron Age, Scythian cultures emerged among the Eurasian nomads, which was characterized by a distinct Scythian art. History Scythia was a loose state or federation covering most of the steppe, that originated as early as the 8th century BCE, composed mainly of people speaking Scythian languages and usually regarded as the first of the nomad empires. The Scythians were Iranic pastorialist tribes who dwelled the Eurasian Steppes from the Tarim Basin and Western Mongolia in Asia to as far as Sarmatia in modern day Ukraine and Russia. The Roman army hired Sarmatians as elite cavalrymen. Europe was exposed to several waves of invasions by horse people, including the Cimmerians. The Scythians and Sarmatians enjoyed a long age of dominion in the 1st Millennium BCE, but at the start of 1st Millennium CE they were displaced by waves of immigrations of other people, to the East, in the steppes east of the Caspian Sea. They were dislocated by the Yuezhi people and were forced to assimilate into them, and many of these Eastern Scythians (Saka) moved and settled in the Parthian Empire in the region later named as Sakastan. The western Iranians, the Alans and Sarmatians, settled down and became the ruling elite of several eastern Slavic tribes and some of these Iranians also assimilated into the Slavic cultures, while others retained their Iranian identity, and their languages are spoken today by the modern Ossetian people.