A discussion of the power of Darius and Cyrus killed, Cambiz and Bardia

The land extensions of Achaemenian government caused power imbalance in Achaemenian family such as that the father and the grandfather of Darius ( that is Vishtasp and Arsham) who had been the relatives of Cyrus and had been settled in margin, had been believed that the governorship is their legal and legitimate right and their goal had been the achievement to power gradually and they had been determined to creating a suitable condition for reigning of their shrewd son that is Darius. As a result Vishtasp and his companions had been killed Cyrus after his fighting with Masagesthes and in the way of returning to home and since the condition had not been suitable for achieving to this power and Darius had been so young, then they had been planned that Darius had gone to Egypt accompanying with Cambyses and after his triennial staying in Egypt and his numerous expeditions to Ethiopia and Libya, he had been killed by Darius and his collaborators in the way of returning to home in Syria. Darius says in Bistoon inscription that Cambyses died in nature and then he fabricates the story of Geumata. After the death of Cambyses, his real brother that is Bardiya had been reign.
Darius had been entered to Bardiya court without any prohibition and had been killed him accompanying with his six collaborators.( it is necessary to mention that till the time of Darius monarchy,