In 1968, Peter Brown read at the Society's Annual General Meeting a paper entitled ‘The Diffusion of Manichaeism in the Roman Empire’. Delivered at a time when little research was being carried out by British scholars either on Manichaeism or on the cultural and religious relationship between the Roman and the Sassanian Empires, it was for many a complete revelation. With consummate skill and vast erudition Brown placed the history of the diffusion of the sect against a background of vigorous and dynamic interchange between the Roman and the Persian Empires. He also mounted a successful challenge on a number of popularly held views on the history of the religion in the Roman Empire. Manichaeism was not to be seen as part of the mirage orientale which fascinated the intellectuals of the High Empire. It was not an Iranian religion which appealed through its foreigness or quaintness. Rather, it was a highly organized and aggressively missionary religion founded by a prophet from South Babylonia who styled himself an ‘Apostle of Jesus Christ’. Brown reminded the audience that ‘the history of Manichaeism is to a large extent a history of the Syriac-speaking belt, that stretched along the Fertile Crescent without interruption from Antioch to Ctesiphon’. Its manner of diffusion bore little or no resemblance to that of Mithraism. It did not rely on a particular profession, as Mithraism did on the army, for its spread throughout the Empire. Instead it developed in the common Syriac culture astride the Romano-Persian frontier which was becoming increasingly Christianized consequent to the regular deportation of whole communities from cities of the Roman East like Antioch to Mesopotamia and adjacent Iran. Manichaeism which originally flourished in this Semitic milieu was not in the strict sense an Iranian religion in the way that Zoroastrianism was at the root of the culture and religion of pre-Islamic Iran. The Judaeo-Christian roots of the religion enabled it to be proclaimed as a new and decisive Christian revelation.