According to the analogy of the Pehlvi inscriptions, decyphered by De Sacy, it was believed that the inscriptions then under consideration, mentioned the name of a king son of another king, that is the names of father and son. M. Grotefend first examined the bas-reliefs at Persepolis, to ascertain the particular age of the Persian kings to which they belonged, in order that he might discover the names applicable to the inscription. A reference to the Greek historians convinced him that he must look for the kings of the dynasty of the Achæmenides, and he accordingly applied their names to the characters of the inscriptions. "These names could obviously not be Cyrus and Cambyses, because the names occurring in the inscriptions do not begin with the same letter; Cyrus and Artaxerxes were equally inapplicable, the first being too short and the latter too long; there only remained therefore the names of Darius and Xerxes;" and these latter agreed so exactly with the characters, that Mr. Grotefend did not hesitate to select them. The next step was to ascertain what these names were in the old Persian language, as they come to us through the Greek, and would of course differ somewhat from the original. The ancient Zend, as preserved in the Zendavesta, furnished the only medium through which the desired information could be obtained.[70] He next ascertained that Xerxes was called _Kshershe_ or _Ksharsha_; and Darius, _Dareush_. A farther examination gave him the name of _Kshe_ or _Ksheio_ for 'king.'[71] The places or groups of characters corresponding with these names, were then analyzed and the value of each character ascertained. These were then applied to other portions of the inscriptions, and led to the translation of two short ones, as well as to the formation of a considerable portion of the alphabet. Such was the result of Professor Grotefend's labors up to the year 1833. His first discovery was made and announced as early as 1802, but an account of his system of interpretation did not appear until 1815, in the appendix to the third German edition of Heeren's Researches. This was afterwards enlarged in the translation of Heeren published at Oxford in 1833, when it was first made known to English readers. In 1837 he published a treatise containing an account of all the Persepolitan inscriptions in his possession, and another in 1840 on those of Babylon.