Although The Egyptian Tale looks like a retelling of a part of the myth of Isis and Osiris, it is obvious that the two brothers Osiris and Typho represent good and bad government. The story, however, is not just a myth, because the man called Osiris can be identified as Aurelian, praetorian prefect of the Eastern Empire during the reign of Arcadius (r.395-408), and one of Synesius' benefactors. The other people in this ancient roman à clef, however, are less easy to identify, but an attempt is made here.
Synesius' Egyptian Tale, 1.2
[1.2.1]  Of souls there are those which are well-born, and those which are ill-born, in such a wise that it might befall a Parthian to be related to a Libyan, and that those whom we call brothers should be in no wise near to one another in kinship of soul, a fact which was indicated in the case of the two Egyptian boys from the moment of their birth, and when they were adult was shown quite clearly. For the younger,note[Osiris/Aurelian.] born and brought up as by a divine destiny, even in childhood’s days was fond of listening, and fond of fables, for the fable is the child’s treatise on philosophy; and as he grew, he always desired training which was in advance of his years. He gave ear to his father, and whatever wisdom was known to each, all that he hungered after, eager to seize first upon al knowledge at once, in puppy fashion, as, of course, all natures do which promise great things. Such natures show impatience and start before their time, already pledging themselves to the beloved goal. Then, again, long before his adolescence, he was even more sedate than a well-bred man of mature age, and he listened with modesty, and when he himself had, on occasion, to speak, whether to ask about what he had been listening to, or with the other purpose, everyone would have noticed him hesitating and blushing. He always made way for the older Egyptians, and gave up his seat to them, and this although he was the son of the ruler of a great kingdom; and respect for those of his own age was ever with him, for it was pre-eminently in his nature to care for the feelings of men. It was indeed difficult at that period of his life to find a man in Egypt for whom the boy had not obtained at least one benefit from his father.
[1.2.2] The elder brother, Typho,note[Unidentified.] on the other hand, was, in a word, a downright boor. All knowledge he hated with his whole heart, both so much as was Egyptian, and also foreign learning, teachers of which the king had placed at the disposal of his son Osiris; and he laughed the whole business to scorn, as though it were idle and calculated to enslave the mind. When he saw his brother conducting himself in an orderly way, and leading a modest life, he thought this cowardly, inasmuch as no one saw him striking a man with his fists, attacking him with kicks, or running in a disorderly fashion, withal that he was nimble, without any spare flesh, and with a body that was a light burden for the soul therein. Then, again, Osiris did not gulp down drink, or give way to peals of vulgar laughter,  which shook the whole body, such as his brother indulged in every day, for Typho deemed these the only acts worthy of a free man, namely to do whatsoever one chanced to desire at a given moment. He was like no one of his race in character, nor indeed like anything human, and he did not, to put it in a nutshell, even resemble himself, for he was a compound of every kind of evil. At one moment he seemed to be stupid, and a mere cumberer of the ground,note[Homer, Iliad 8.104.] only keeping from his sleep long enough to fill his belly and to take other provisions for the route of slumber; at another he would neglect the moderate necessities of nature to indulge in gross horse-play, and to annoy his own equals in age and his elders. He admired strength of body as being the ultimate good, but he used it ill, wrenching off doors, throwing clods of earth, and rejoicing if anyone was hurt thereby, or if he had done any other mischief, as though this bore witness to prowess. He flamed up with untimely lust, and was violent in seeking amorous encounters. Further, envy of his brother smoldered within him, and hatred of the Egyptians, because they, the people, gave honor to Osiris, both in speech and in song, and at home in their common religious rites, all, everywhere, prayed of the gods that every sort of good thing might be his. Such was the man and so regarded. Then again, Typho took to himself bands of senseless boys, for no other reason (since it was not his nature to care for anyone in his heart) than that he might have some partisans who did not hold the views of Osiris. It was easy enough for anyone to win this man’s good graces, and to get from Typho anything that young men desire, by merely whispering something tending to calumniate Osiris. So from childhood did the respective characters of the two foretell the difference of their lives