The tide of foreign conquest, which had scarce begun to flow before the death of Abú Bakr, swept with amazing rapidity over Syria and Persia in the Caliphate of ‘Umar b. al-Khaṭṭáb (634-644), and continued to advance, though with diminished fury, under the Prophet's third successor, ‘Uthmán. We may dwell for a little on the noble figure of ‘Umar, who was regarded by good Moslems in after times as an embodiment of all the virtues which a Caliph ought to possess. Probably his character has been idealised, but in any case the anecdotes related of him give an admirable picture of the man and his age. Here are a few, taken almost at random from the pages of Ṭabarí. [Sidenote: His simple manners.] [Sidenote: His sense of personal responsibility.] [Sidenote: The Caliph as a policeman.] [Sidenote: His strictness towards his own family.] [Sidenote: Instructions to his governors.] One said: "I saw ‘Umar coming to the Festival. He walked with bare feet, using both hands (for he was ambidextrous) to draw round him a red embroidered cloth. He towered above the people, as though he were on horseback."[348] A client of (the Caliph) ‘Uthmán b. ‘Affán relates that he mounted behind his patron and they rode together to the enclosure for the beasts which were delivered in payment of the poor-tax. It was an exceedingly hot day and the simoom was blowing fiercely. They saw a man clad only in a loin-cloth and a short cloak (_ridá_), in which he had wrapped his head, driving the camels into the enclosure. ‘Uthmán said to his companion, "Who is this, think you?" When they came up to him, behold, it was ‘Umar b. al-Khaṭṭáb. "By God," said ‘Uthmán, "this is _the strong, the trusty_."[349]--‘Umar used to go round the markets and recite the Koran and judge between disputants wherever he found them.--When Ka‘bu ’l-Aḥbár, a well-known Rabbin of Medína, asked how he could obtain access to the Commander of the Faithful,[350] he received this answer: "There is no door nor curtain to be passed; he performs the rites of prayer, then he takes his seat, and any one that wishes may speak to him."[351] ‘Umar said in one of his public orations, "By Him who sent Muḥammad with the truth, were a single camel to die of neglect on the bank of the Euphrates, I should fear lest God should call the family of al-Khaṭṭáb" (meaning himself) "to account therefor."[352]--"If I live," he is reported to have said on another occasion, "please God, I will assuredly spend a whole year in travelling among my subjects, for I know they have wants which are cut short ere they reach my ears: the governors do not bring the wants of the people before me, while the people themselves do not attain to me. So I will journey to Syria and remain there two months, then to Mesopotamia and remain there two months, then to Egypt and remain there two months, then to Baḥrayn and remain