The roots of every new civilisation must be nourished by the achievements of its precursors. In the case of Islam these precursors were to be found in the Hellenistic, Roman and Byzantine civilisations, with lesser, but still significant, influences from India and China.

When Alexander the Great died in 323 BC his conquests stretched from Greece, Asia Minor, Syria and Egypt through Persia and Afghanistan and as far as the River Indus. Although his empire did not survive his death as an entity, he had managed to impose a single political unit on a larger part of the western world than anyone before him. After he died the major part of the empire was divided among his generals: Antigonus ruled Asia Minor, Syria and Palestine; Seleucus ruled Mesopotamia, Persia and the eastern parts to the borders of India; and Ptolemy ruled Egypt and Libya. The division lasted to the battle of Ipsus in 301 BC, when Seleucus added Asia Minor and Syria to his possessions. The Seleucids only managed to hold such a vast expanse of territory for some fifty years, before the Parthians took control of eastern Mesopotamia and eventually – around the end of the third century BC – most of the eastern parts of the Seleucid kingdom.

The Greek kingdom of Bactria, however, arose in 254 BC – hence almost at the same time as Parthia. It was founded by a Greek governor, Diodatus, who made himself independent of the Seleucids. Little is known about this kingdom, which was centred on the Rivers Oxus and Sughd (on which are the cities of Bukhārā and Samarqand) and at one time extended to the north Indian plain. Eventually, after endemic warfare with the Seleucids and Parthians, the Bactrian Kingdom was incorporated into the Parthian domains about 140 BC. To us the importance of Bactria lies in its position as a commercial nexus between East Asia and India on the one hand, and the Middle East and Mediterranean on the other.