Achaemenid dynasty

The Achaemenid dynasty (Greek: Ἀχαιμενίδαι; "Achaimenídai", in Old Persian "Hakhāmanišiya"; ) was an ancient Persian royal house. They were the ruling dynasty of the Achaemenid Empire from about 700 to 330 BC.
The rulers from the Achaemenid dynasty, starting with Cambyses II, who conquered Egypt, the historian Manetho placed as pharaohs in the Twenty-seventh Dynasty of Egypt.
Origins.
The history of the Achaemenid dynasty is mainly known thanks to Greek historians as Herodotus, Ctesias and Xenophon, tales of Old Testament books, and native Iranian sources. According to Herodotus, Achaemenids were a clan from the tribe of the Pasargadae and probably settled surrounding the sites of Pasargadae. They possibly ruled over other Persian tribes in the 9th century B.C.
Darius traced his genealogy to Achaemenes, an unknown lineage named after Haxāmaniš. However, there's no evidence about a king called Achaemenes.
Dynasty.
Kingship was hereditary within the Achaemenid dynasty. The last element of the King's title was always "an Achaemenid". Succession was designated by the King (usually the first-born son). From Darius I to Artaxerxes II, it was usual a synarchy between the father and the son.