It is not clear where the earliest Tibetans originated, since records and very scarce and archaeological excavation limited. Early Chinese records speak of a people called the Ch’iang, who are also referred to as Fa, also Baut, Puat and Bod, depending on the period and who is giving the name. The original character for Ch’iang combined ‘man’ and ‘sheep’ and so it seems reasonable to assume that these were nomads. Initially, they appear to have appeared on the eastern edges of what is now recognised as Tibetan territory but subsequently they suffered a military reverse and were obliged to retreat up the slopes. They were just one of an unknown number of different tribes operating on the outskirts of the Chinese polity at this time, some of which eventually migrated westwards towards the Arab lands and India and also into what then seems likely to have been the largely uninhabited reaches of Central Asia. It was from these tribes that the mighty conquerors, the Hsiung-nu and the Huns (who may have been one and the same), the Skythians, the Magyars, the Mongols and the Turks. Although their lifestyles had many similarities, they also differed owing to the geography of the land that they occupied and their relationships with their neighbours. The intermarriage, constant raiding and making and breaking of alliances also contributed to a certain commonality of cultural and institutions.
It was the Yarlung Dynasty which was the first known to have conquered the land of Tibet and, although it is not known where they derived or, really, who they were, they are sure to have been steppe warriors rather than farmers from the agricultural south. The first king is said to have descended from the sky, which seems unlikely on a purely literal basis but a successor, Dri gum btsanpo, is recorded as having cut the rope to the sky. This suggests that, as is common with rulers from across Asia and, indeed, further afield, that Dri gum btsanpo in one way or another had achieved power over the state and it was necessary for his publicists, to borrow a modern term, to demonstrate that he had a divine origin and that Heaven smiled upon him. It was necessary, therefore, that he be both related to the long list of (probably largely imaginary or legendary) kings who preceded him but was also different from them – i.e. he was real and had the ability to come and smite his enemies.