they had fortune on their side. They crossed the fertile land to the north of Ḥīra unmolested and plundering as they went; Ullais was also put under contribution, and suddenly they appeared before Ḥīra. The town was well fortified, but the garrison was palpably insufficient for an open battle. And what was the use of resistance within the walls if their rich lands around were to be desolated? Thinking thus they quickly resolved to pay a ransom, especially as the Arabs only demanded the ridiculously small sum of 60,000 dirhams. To the Arabs this seemed an enormous booty. Elated with victory they withdrew, and Ḥīra was thus saved for the time being. It is scarcely conceivable that the payment of this sum was regarded as an annual tribute. After this expedition Khālid marched on with his braves, by command of the Caliph, right through the enemy's territory, appearing in all directions with lightning speed and disappearing again with equal rapidity, from Ḥīra through Palmyra to Syria where he appeared, suddenly and unexpectedly, under the walls of Damascus. This expedition, so woven round with legendary lore, and apart from that a military masterpiece, shews better than anything else that the conquest of Persia was not premeditated, and that the Muslims were making their main effort in Syria. The raid against Ḥīra was made at a time of the greatest confusion in Persia, but few months after the accession of Yezdegerd, when the central authority was to some extent restored by his general Rustam. Thereupon a counter-raid was prepared against the plunderers. Muthannā sought help from Medina. This was in the early days of Omar's government, and he granted the request only with a certain amount of reluctance, refusing to spare his best troops from Syria. The combined troops of the Bakr and of Medina were few and badly handled, and in a second expedition they were almost annihilated; in the so-called Bridge battle Muthannā saved with difficulty the remnants of the Muslim army (26 Nov. 634). It was in consequence of this disaster that Omar, a year later (635), was led to a more energetic interference in the conditions of the 'Irāḳ, but even then his actions were somewhat dilatory. Of this it will be necessary to speak later, if only briefly. For a history of the Middle Ages the expansion of the Arabs in Mediterranean territories is of much greater importance.
The Arabian records of these events are not only distorted by lies, but are terribly confused: especially in their chronology. Fortunately we are better informed through some of the Byzantine writers, especially Theophanes. It was not the sagacity of the Caliphs, wanting to conquer the world, that flung the Muslim host on Syria, but the Christian Arabs of the border districts who applied to the powerful organisation of Medina for assistance. We are told very little about the relations between Mahomet and the great tribes of North Arabia, such as the Judhām, Kalb, Ḳuḍā'a, Lakhm, Ghassān; but the defeat of Mu'ta shews that they were enemies of Medina. It was only the expedition
