Diodorus of Sicily: Greek historian, author of the Library of World History. His activities can be dated between 60 and 30 BCE.
In August 338, the Macedonian king Philip defeated an army of Athenians and Thebans on the plain of Chaeronea, a town in Central Greece. While the Macedonian right wing pretended to retreat and lured the Athenians (the Greek left wing) to advance, a gap was created between the Athenians and the Thebans on the Greek right wing. The decisive charge was led by Philip's son Alexander, who sped with the Macedonian through the gap and broke the Greek line.
The Macedonian victory meant the end of the independence of the Greek towns and marks the beginning of the career of Alexander. The following account is by Diodorus of Sicily, World history, 16.85.5-86.6.
The translation was made by Michael Crawford and David Whitehead.
The battle of Chaeronea
[16.85.5] So Philip, having failed to get the alliance of the Boeotians, nevertheless decided to fight both of the Athenians and Boeotians together. So he waited for the last of his allies to arrive and then marched into Boeotia, with more than 30,000 infantry and no less than 2,000 cavalry.
[16.85.6] Both sides were eager for the battle and were well matched in intention, zeal and courage, but the king had the advantage in numbers and in generalship.
[16.85.7] For henote[Philip.] had fought many battles of different sorts and had been victorious in most cases, so that he had wide experience of military operations. On the Athenian side, the best of their commanders were dead, Iphicrates, Chabrias and Timotheus too; and the best of those who were left, Chares, was no better than any soldier in the activity and counsel required of a commander.
[16.86.1] The armies deployed at dawn,note[East of Chaeronea.] and the king stationed his son Alexander, young in agenote[He was eighteen years old.] but outstanding for his bravery and swiftness of action, on one wing, placing with him his best commanders, while he himself at the head of an élite corps exercised the command over the other;note[Philip's men stood on the right wing, Alexander commanded the left.] and he deployed individual units where the occasion required.
[16.86.2] On the other side, the Athenians, dividing the line according to nationality, assigned one wing to the Boeotians and commanded the other themselves.note[The Athenians took the left wing (opposite Philip); the Thebans were standing opposite Alexander on the right.] The battle was hotly contested for a long time and many fell on both sides, so that for a while the struggle permitted hopes of victory to both.
[16.86.3] Then Alexander, eager to show his father his prowess, and second to none in excess of zeal, and also with many good men at his side, first succeeded in breaking the solid front of the enemy line and, striking down many, he fought those opposite him into the ground.note[His charge was aimed at the extreme right of the Thebans, where they had placed their élite troops, the Sacred band.] As the same success was won by his companions, gaps in the solid front were opened.
[16.86.4] Corpses piled up, until finally those with Alexander forced their way through and put their opponents to flight.
Then the king also in person hazarded an advance,note[Philip's men had pretended to retreat.] not conceding credit for victory even to Alexander; he first forced back the troops stationed opposite him and then by compelling them to flee became the man responsible for the victory.
[16.86.5] More than 1,000 Athenians fell in the battle and no less than 2,000 were captured. Likewise, many of the Boeotians were killed and not a few taken prisoner.
[16.86.6] After the battle Philip raised a trophy, gave up the dead for burial, gave sacrifices to the gods for victory, and rewarded according to their deserts those of his men who had distinguished themselves for bravery.