Plutarch, Alexander
Bernadotte Perrin, Ed.

9. While Philip was making an expedition against Byzantium, ¹ Alexander, though only sixteen years of age, was left behind as regent in Macedonia and keeper of the royal seal, and during this time he subdued the rebellious Maedi, and after taking their city, drove out the Barbarians, settled there a mixed population, and named the city Alexandropolis. [2] He was also present at Chaeroneia and took part in the battle against the Greeks, ² and he is said to have been the first to break the ranks of the Sacred Band of the Thebans. And even down to our day there was shown an ancient oak by the Cephisus, called Alexander's oak, near which at that time he pitched his tent; and the general sepulchre of the Macedonians is not far away.

[3] In consequence of these exploits, then, as was natural, Philip was excessively fond of his son, so that he even rejoiced to hear the Macedonians call Alexander their king, but Philip their general. However, the disorders in his household, due to the fact that his marriages and amours carried into the kingdom the infection, as it were, which reigned in the women's apartments, produced many grounds of offence and great quarrels between father and son, and these the bad temper of Olympias, who was a jealous and sullen woman, made still greater, since she spurred Alexander on. [4] The most open quarrel was brought on by Attalus at the marriage of Cleopatra, a maiden whom Philip was taking to wife, having fallen in love with the girl when he was past the age for it. ³ Attalus, now, was the girl's uncle, and being in his cups, he called upon the Macedonians to ask of the gods that from Philip and Cleopatra there might be born a legitimate successor to the kingdom. At this Alexander was exasperated, and with the words, ‘But what of me, base wretch? Dost thou take me for a bastard?’ threw a cup at him. [5] Then Philip rose up against him with drawn sword, but, fortunately for both, his anger and his wine made him trip and fall. Then Alexander, mocking over him, said: ‘Look now, men! here is one who was preparing to cross from Europe into Asia; and he is upset in trying to cross from couch to couch.’ After this drunken broil Alexander took Olympias and established her in Epirus, while he himself tarried in Illyria.

[6] Meanwhile Demaratus the Corinthian, who was a guest-friend of the house and a man of frank speech, came to see Philip. After the first greetings and welcomes were over, Philip asked him how the Greeks were agreeing with one another, and Demaratus replied: ‘It is surely very fitting, Philip, that thou shouldst be concerned about Greece, when thou hast filled thine own house with such great dissension and calamities.’ Thus brought to his senses, Philip sent and fetched Alexander home, having persuaded him to come through the agency of Demaratus.