Plutarch, Life of Alexander 6
1 Once upon a time Philoneicus the Thessalian brought Bucephalas, offering to sell him to Philip for thirteen talents,and they went down into the plain to try the horse, who appeared to be savage and altogether intractable, neither allowing any one to mount him, nor heeding the voice of any of Philip's attendants, but rearing up against all of them. 2 Then Philip was vexed and ordered the horse to be led away, believing him to be altogether wild and unbroken; but Alexander, who was near by, said: "What a horse they are losing, because, for lack of skill and courage, they cannot manage him!" 3 At first, then, Philip held his peace; but as Alexander many times let fall such words and showed great distress, he said: "Dost thou find fault with thine elders in the belief that thou knowest more than they do or art better able to manage a horse?" 4 "This horse, at any rate," said Alexander, "I could manage better than others have." "And if thou shouldst not, what penalty wilt thou undergo for thy rashness?" "Indeed," said Alexander, "I will forfeit the price of the horse." 5 There was laughter at this, and then an agreement between father and son as to the forfeiture, and at once Alexander ran to the horse, took hold of his bridle-rein, and turned him towards the sun; for he had noticed, as it would seem, that the horse was greatly disturbed by the sight of his own shadow falling in front of him and dancing about. 6 And after he had calmed the horse a little in this way, and had stroked him with his hand, when he saw that he was full of spirit and courage, he quietly cast aside his mantle and with a light spring safely bestrode him. 7 Then, with a little pressure of the reins on the bit, and without striking him or tearing his mouth, he held him in hand; but when he saw that the horse was rid of the fear that had beset him, and was impatient for the course, he gave him his head, and at last urged him on with sterner tone and thrust of foot. 8 Philip and his company were speechless with anxiety at first; but when Alexander made the turn in proper fashion and came back to them proud and exultant, all the rest broke into loud cries, but his father, as we are told, actually shed tears of joy, and when Alexander had dismounted, kissed him, saying: "My son, seek thee out a kingdom equal to thyself; Macedonia has not room for thee."