 Within the text, the father and son of the king had different groups of symbols for names so Grotefend assumed that the king must have been Darius.These connections allowed Grotefend to figure out the cuneiform characters that are part of Darius, Darius's father Hystaspes, and Darius's son Xerxes.Grotefend's contribution to Old Persian is unique in that he did not have comparisons between Old Persian and known languages, as opposed to the decipherment of the Egyptian hieroglyphics and the Rosetta Stone.