These traditions have their historical setting in the reign of Tiridates, and of Chosroes the father of Tiridates. [69] Just as there was an Arsacid dynasty in Armenia, dating and originating in the Parthian conquests and supremacy, so also was there an Arsacid dynasty of Persia. The Persian king at the time of Chosroes was a kinsman of the latter, called Ardavan, who was overthrown (A.D. 227) by a Persian prince of the province of Fars, named Ardashir. [70] His dynasty, a very powerful one, known as the Sassanid dynasty, supplanted the Arsacid dynasty of Persia. Chosroes of Armenia, fearing future difficulty with the new Persian monarch, ardently supported his dethroned kinsman. The next year (228), therefore, he led a huge army beyond the frontiers of Persia, and laid waste her provinces to the gates of Ctesiphon. [71] The war was continued for ten years, during which time the Armenian capital, Vagharshapat, was filled with the booty of successful raids. The reigning Caesar, Severus, also alarmed by the success of the new Persian king, headed a Roman army against Ardashir. Realizing the jeopardy of his position, the Persian resolved to put Chosroes out of the way by whatever means possible. A Parthian of the royal blood, Anak by name, consented to execute his king's desire, and went with his family to Vagharshapat as a refugee. A friendship sprang up between himself and his future victim, enabling him to execute his purpose, which he did in company with his brother while preparation was being made for a spring campaign. But the murderers were cut off in their escape by Armenian horsemen and precipitated into the Araxes, while the dying king gave orders to massacre the family of Anak. Only two of the children were rescued, one of whom was Gregory, the Illuminator, founder of the Armenian national church, called also the Gregorian church. The child Gregory was taken to Cesarea where he was educated in the tenets of Christianity. [72] Ardashir died shortly after the murder of his foe, and thus failed to follow up his advantage except for a few raids into Armenian territory. Tiridates, a child at this time, was the oldest son of Chosroes, and as heir to the Armenian throne was the chief obstacle in the way of the ambitions of his uncles, whose treatment of the young king compelled him to take refuge in Rome where he was educated. [73] Having distinguished himself by personal bravery in a Gothic campaign, his nation's dominions were restored to him by the support of a Roman army, for during his absence Armenia was invaded by Shapur, the successor of Ardashir. The Persian king had taken advantage of the disputes of Tiridates' uncles. The remainder of the story is legendary.