From this, Grotefend concluded that the groups of signs “X” “Y” and “Z” represented proper names, and that as “X” and “Y” were accompanied by “king,” they must be king’s names, and lastly Achaemenian kings’ names, for ancient writers stated that these palaces at Persepolis were built by Achaemenian kings, and furthermore their position suggested that these proper names must stand in genealogical relation to each other. In I “X” must be the son of “Z,” and in II “Y” must be the son of “X”; “X” and “Y” are accompanied with the sign for “king,” “Z” is not, therefore “Z” the father of “X” is not a king, and consequently “X” is presumably the founder of the dynasty. But apart from this hypothesis, some of the names of the five kings composing the (fortunately) short Achaemenian Dynasty—Cyrus, Cambyses, Darius, Xerxes and Artaxerxes—were at once ruled out of court: thus Cyrus and Cambyses were out of the question, for “X” and “Y” did not commence with the same cuneiform letter (it must be remembered that it had already been rightly assumed that the system was an alphabetic one), and moreover Cyrus’ father and son were both named Cambyses, and accordingly if “X” were Cyrus then “Y” and “Z” should be the same, which they are not. Cyrus and Artaxerxes were likewise disqualified, as there was no such discrepancy in the length of the words, there thus remained only Darius and Xerxes to be considered, and as “X’s” father “Z” is not called king, and it is further known that Hystaspes the father of Darius is not styled “king” by the classical writers, “X” was rightly assumed to be Darius. Having ascertained the oldest forms of the names of the Achaemenian kings in question from the classical writers, and Hebrew and Persian literature, he applied these forms to the groups of cuneiform signs which he had been led to believe they represented, and he found the respective groups contained the same number of individual signs as the proper names in question contained letters, and for “X” he accordingly read—D A R — — U SH = Darius “Z” he read—G O SH T A S P = Hystaspes — the Zend form of the name.