The territories of modern-day Mongolia and Inner Mongolia in ancient times was inhabited by nomadic tribes. The cultures and languages in these areas were fluid and changed frequently. The use of horses to herd and move started during the Iron Age. North-western Mongolia was Turkic while south-western Mongolia had come under Indo-European (Tocharian and Scythian) influence. In antiquity, the eastern portions of both Inner and Outer Mongolia were inhabited by Mongolic peoples descended from the Donghu people and numerous other tribes These were Tengriist horse-riding pastoralist kingdoms that had close contact with the agrarian Chinese. As a nomadic confederation composed of various clans the Donghu were prosperous in the 4th century BC, forcing surrounding tribes to pay tribute and constantly harassing the Chinese State of Zhao (325 BC, during the early years of the reign of Wuling). To appease the nomads local Chinese rulers often gave important hostages and arranged marriages. In 208 BC Xiongnu emperor Modu Chanyu, in his first major military campaign, defeated the Donghu, who split into the new tribes Xianbei and Wuhuan. The Xiongnu were the largest nomadic enemies of the Han Dynasty fighting wars for over three centuries with the Han Dynasty before dissolving. Afterwards the Xianbei returned to rule the Steppe north of the Great Wall. The titles of Khangan and Khan originated from the Xianbei.