There has been virtually no research in the west on the history of Chinese astrology, perhaps because Europeans have always been far more interested in the alternative, and highly intriguing divinatory tool, the Book of Changes, or I Ching. The fact that this oracular system should have evolved indicates the extent to which China provided fertile ground for the development of astrology, but Chinese astrology never achieved either the complexity and sophistication, or the dominance as a method of divination, that it did in the west.
    
    The relative geographical isolation of China from the rest of the World accounts for the substantial differences between Chinese and western astrology. For example the circumpolar constellations, those that surrounded the pole star, were considered particularly important, and it was this band that has divided into the 28 hsui.
    
    However, the possibility of links between Chinese and western astrologers is stronger than might be thought at first. It has been suggested that Indian and Chinese astrologers were in loose contact via the Himalayas, but in fact 2,000 years ago Persia would have been far more accessible to the Chinese than would India. Central Asia until about 1,500 A.D. was always the centre of, or close to the centre of, some powerful Empire, and the entire area, which is now considered remote and inhospitable, was covered by great caravan routes and prosperous trading centres. Thus we can imagine Persian and Chinese scholars meeting and, in discussions on the nature of the Universe, confiding in each other the techniques of astrology. This, however, is pure speculation, and there is no record of a Chinese astronomer visiting Persia until the 13th century A.D.
    
    The coincidence between Chinese and western astrology goes beyond the use of 28 hsui or 12 animal types. A set of predictions exists in the Shih Chi (historical record) of Ssuma Chien, compiled around 100 B.C. but containing much earlier material. The similarity between these omens, which deal with the rising of the planets, their conjunctions and paths through the stars, and the Enuma Anu Enlil is striking, and strong enough to suggest communication between Chinese and Mesopotamian astrologers before 100 B.C.
    
    It is also of interest that natal astrology developed in China at around the time of Christ, at the same period as it was developed in the west by Greeks and Persians. This also suggests that astrologers in China were not unaware of the state of astrology in the west, and while accepting that we have no direct evidence of communication between the two cultures, such evidence may lie in the cities of central Asia long abandoned and lost to nature. The earliest Chinese astrologer who is known to us is Wei Ning, who was born around 550 but of his contribution to the art, and of his predecessors and successors almost nothing is known. Chinese astrology today has spread worldwide with the migrations of the Chinese, and only now is beginning to have an impact on the thought of western astrologers.