We begin by posting the story as given by Francis Grant in his Oriental Philosophy:
"Thus, with the faith of his father, Mani had already accepted a varied gospel, and during his boyhood years he is said to have had visions and revelations. But even before his birth, the Manichaean tradition tells us, his mother had been visited by the Angel Tawn [Twin] who had brought her the annunciation of her mission.
"Returning to his native land, he brought these arts back to Persia - to a soil fertile for artistic creation. But this time Shapur was not open to his gospel, for the Magian priests by now so influential in his court, denounced Mani and he was forced to flee. With the accession of Shapur's successor, Hamiz, the young Persian apologist returned to his home, carrying on his teaching without molestation, but watched with vengeful eyes by the Magians, who had now lost favor. No sooner however did Hamiz die and Bahram come to the throne, than the Magians returned to power.
Mani's father himself must have displayed considerable activities as a religious reformer and have been a kind of forerunner of his more famous son, in the first years of whose public life he had some share. Through his mother he was related to the Parthian royal family (overthrown in 224) [Arsacids, who were a dynasty of Parthian kings who ruled Iran between 247 B.C.- 224 A.D.].
The boy was born in the village of Mardinu in Babylonia near Seleucia-Ctesiphon, according to other accounts in the town Abrumya, from a mother of noble (Arsacide) descent.
The city was called Mardinu- now Mardin in Turkey.
Here is a map. Mardin is near the Syrian border: