About four years after the triumph of the Persian war, the repose of Heraclius and the empire was again disturbed by a new enemy, the power of whose religion was more strongly felt, than it was clearly understood, by the Christians of the East. In his palace of Constantinople or Antioch, he was awakened by the invasion of Syria, the loss of Bosra, and the danger of Damascus. An army of seventy thousand veterans, or new levies, was assembled at Hems or Emesa, under the command of his general Werdan: and these troops consisting chiefly of cavalry, might be indifferently styled either Syrians, or Greeks, or Romans: _Syrians_, from the place of their birth or warfare; _Greeks_ from the religion and language of their sovereign; and _Romans_, from the proud appellation which was still profaned by the successors of Constantine. On the plain of Aiznadin, as Werdan rode on a white mule decorated with gold chains, and surrounded with ensigns and standards, he was surprised by the near approach of a fierce and naked warrior, who had undertaken to view the state of the enemy. The adventurous valor of Derar was inspired, and has perhaps been adorned, by the enthusiasm of his age and country. The hatred of the Christians, the love of spoil, and the contempt of danger, were the ruling passions of the audacious Saracen; and the prospect of instant death could never shake his religious confidence, or ruffle the calmness of his resolution, or even suspend the frank and martial pleasantry of his humor. In the most hopeless enterprises, he was bold, and prudent, and fortunate: after innumerable hazards, after being thrice a prisoner in the hands of the infidels, he still survived to relate the achievements, and to enjoy the rewards, of the Syrian conquest. On this occasion, his single lance maintained a flying fight against thirty Romans, who were detached by Werdan; and, after killing or unhorsing seventeen of their number, Derar returned in safety to his applauding brethren. When his rashness was mildly censured by the general, he excused himself with the simplicity of a soldier. "Nay," said Derar, "I did not begin first: but they came out to take me, and I was afraid that God should see me turn my back: and indeed I fought in good earnest, and without doubt God assisted me against them; and had I not been apprehensive of disobeying your orders, I should not have come away as I did; and I perceive already that they will fall into our hands." In the presence of both armies, a venerable Greek advanced from the ranks with a liberal offer of peace; and the departure of the Saracens would have been purchased by a gift to each soldier, of a turban, a robe, and a piece of gold; ten robes and a hundred pieces to their leader; one hundred robes and a thousand pieces to the caliph. A smile of indignation expressed the refusal of Caled. "Ye Christian dogs, you know your option; the Koran, the tribute, or the sword.