The best resistance made to Sapor was by Odenatus, a Syrian chief, and his beautiful Arabian wife Zenobia, who held out the city of Palmyra, on an oasis in the desert between Palestine and Assyria, till Sapor retreated.  Finding that no notice was taken of them by Rome, they called themselves Emperor and Empress.  The city was very beautifully adorned with splendid buildings in the later Greek style; and Zenobia, who reigned with her young sons after her husband’s death, was well read in Greek classics and philosophy, and was a pupil of the philosopher Longinus.  Aurelian, becoming Emperor of Rome, came against this strange little kingdom, and was bravely resisted by Zenobia; but he defeated her, made her prisoner, and caused her to march in his triumph to Rome.  She afterwards lived with her children in Italy.

Aurelian saw perils closing in on all sides of the empire, and thought it time to fortify the city of Rome itself, which had long spread beyond the old walls of Servius Tullus.  He traced a new circuit, and built the wall, the lines of which are the same that still enclose Rome, though the wall itself has been several times thrown down and rebuilt.  He also built the city in Gaul which still bears his name, slightly altered into Orleans.  He was one of those stern, brave Emperors, who vainly tried to bring back old Roman manners, and fancied it was Christianity that corrupted them; and he was just preparing for a great persecution when he was murdered in his tent, and there were three or four more Emperors set up and then killed almost as soon as their reign was well begun.  The last thirty of them are sometimes called the Thirty Tyrants.  This power of the Praetorian Guard, of setting up and pulling down their Emperor as being primarily their general, lasted altogether fully a hundred years.

[Illustration:  COIN OF SEVERUS]

CHAPTER XXXVI.

THE DIVISION OF THE EMPIRE.

284-312.

A Dalmatian soldier named Diocles had been told by a witch that he should become Emperor by the slaughter of a boar.  He became a great hunter, but no wild boar that he killed seemed to bring him nearer to the purple, till, when the army was fighting on the Tigris, the Emperor Numerianus died, and an officer named Aper offered himself as his successor.  Aper is the Latin for a boar, and Diocles, perceiving the scope of the prophecy, thrust his sword into his rival’s breast, and was hailed Emperor by the legions.  He lengthened his name out to Diocletianus, to sound more imperial, and began a dominion unlike that of any who had gone before.  They had only been, as it were, overgrown generals, chosen by the Praetorians or some part of the army, and at the same time taking the tribuneship and other offices for life.  Diocletian, though called Emperor, reigned like the kings of the East.  He broke the strength of the Praetorians, so that they could never again kill one Emperor and elect another as before; and he never would visit Rome lest he should be obliged to acknowledge the authority of the Senate, whose power he contrived so entirely to take away, that thenceforward Senator became only a complimentary title, of which people in the subdued countries were very proud.