Titus Livius (Livy), The History of Rome, Book 42
Evan T. Sage, Ph.D. and Alfred C. Schlesinger, Ph.D., Ed.

15. After the embassies had been dismissed, when Harpalus with all possible speed had returned to Macedonia and reported to the king that he had left the Romans not yet, indeed, preparing for war, [2??] but so unfriendly that it was easily evident that they would not try to delay it, then Perseus likewise, not to mention the fact that he believed that this would be the outcome, was now even eager for war, believing that he was at the height of his power. [3] He was more specially incensed at Eumenes; beginning the war with an attempt on his life, he employed Evander the Cretan, a commander of auxiliaries, and three Macedonians who were accustomed to the performance of such crimes, to murder the king, and he gave them a letter to his friend Praxo, a woman high in influence and wealth at Delphi. [4] It was generally known that Eumenes was intending to go up to Delphi to offer sacrifices to Apollo. The plotters, led by Evander, going in advance and carefully reconnoitering the ground, were searching for nothing else than a suitable place at which to accomplish their purpose. [5] As travellers ascend to the temple from Cirrha, before they reach the districts where buildings abound, there was a wall on the left beside a path which stood out only a little distance from the lower courses of the wall, where men could only pass in single file; the right side, in consequence of a land-slide, had fallen away [p. 337]to a considerable depth. [6] They concealed themselves¹ behind the wall, building up steps so that they might hurl their missiles, as from a rampart, upon the king as he passed. [7] At first he approached from the sea surrounded by a crowd of his friends and courtiers, then the narrowness of the road gradually thinned out the line. [8] When they came to that place where they had to walk in single file, the first to enter the path was Pantaleon, a leading citizen of Aetolia, with whom the king had begun a conversation. [9] Then the plotters, springing up, rolled down two huge stones, one of which struck the king's head, the other his shoulder; and being stunned he fell from the path down the slope, and many stones were heaped upon him as he now lay prostrate. [10] And the rest, even the crowd of his friends and courtiers, scattered after they saw his fall; Pantaleon on the other hand courageously remained to defend the king.