During this time, Alexander took the Persian title "King of Kings" (Shahanshah) and adopted some elements of Persian dress and customs at his court, notably the custom of proskynesis, either a symbolic kissing of the hand, or prostration on the ground, that Persians paid to their social superiors.[101][102] The Greeks regarded the gesture as the province of deities and believed that Alexander meant to deify himself by requiring it. This cost him much in the sympathies of many of his co (more...)untrymen.[102] A plot against his life was revealed, and one of his officers, Philotas, was executed for failing to bring the plot to his attention. The death of the son necessitated the death of the father, and thus Parmenion, who had been charged with guarding the treasury at Ecbatana, was assassinated by command of Alexander, so he might not make attempts at vengeance. Most infamously, Alexander personally slew the man who had saved his life at Granicus, Cleitus the Black, during a drunken argument at Maracanda.[103] Later, in the Central Asian campaign, a second plot against his life was revealed, this one instigated by his own royal pages. His official historian, Callisthenes of Olynthus (who had fallen out of favor with the king by leading the opposition to his attempt to introduce proskynesis), was implicated in the plot; however, there has never been consensus among historians regarding his involvement in the conspiracy. (less)