Synesius of Cyrene (c.370-c.413) was a Neo-Platonic philosopher who became bishop of Ptolemais in the Cyrenaica. He left behind a small corpus of texts that offer much information about daily life in Late Antiquity, and about the christianization of the Roman world.
The Eulogy of Baldness shows Synesius' lighter side: he defends his baldness against the speech In Praise of Hair by the sophist-philosopher Dio Chrysostom ("tongue of gold").
The text is offered here in the translation by A. Fitzgerald. The green four-digit numbers are page numbers of the Migne edition.
An anecdote about Alexander
  A Macedonian with hair unusually long and a thick drooping beard, was attacking a Persian, but the Persian, although in danger, with excellent judgment drops the well-known oblong shield and spears from his hands, as insufficient for coping with the Macedonian. He then charges him, and contriving to slip in under his enemy's guard, seizes him by the beard and hair, and thus throws the soldier, who had not struck a blow, to the ground, drawing him to himself by the hair like a fish, and once fallen slays him with his drawn scimitar.
 Some other Persian also saw this, and another and another, and soon they were all throwing away their shields, and in full pursuit of the enemy through the plain, where one would catch one man buy his hair, and another, another; for it now passed through the Persian army like a signal that these troops could be captured by their hair, and no one probably of Alexander's phalanx stood his ground except that portion which was bald.  Meantime the king was in sore straits, exposed to unarmed men, against whom when fully armed his army was irresistible.
 As it was, Alexander might have been compelled to retreat to Cilicia in disgrace, and to become the laughing-stock of the Greeks, as one who had been defeated in a battle of the hair! But as matters were (for it was already destined that the Heraclids should deprive the Achaemenids of their scepters), speedily understanding the danger, he orders the trumpets to sound the retreat, and when he has led his army as far away as possible, and has placed it in a good position, he lets loose the barbers upon it, and induced by the gifts of the king, they shaved the Macedonians en masse.
 As to Darius and the Persians, the campaign no longer proceeded according to their hopes, for as there was no longer anything to hold on to, they were condemned to struggle in armor against much superior adversaries.