Nothing now remained to complete the triumph of the invaders but the capture of Jerusalem itself; accordingly a little time after the decisive battle of Yarmuk (A.D. 636), Abu Obeidah prepared to march upon the Holy City. Yezid ibn abi Sufiyân was sent forward with a detachment of five thousand men ; Abu 'Obeidah himself brought up the main body a few days later, and was joined shortly after by the division under 'Amer ibn el 'As. Desiring to afford the inhabitants every opportunity of coming to terms without further bloodshed, the general, before actually commencing hostilities, halted at the ford of the Jordan, and indited a letter to the Christian Patriarch and people of JElia, demanding their immediate submission, and requiring them either to embrace the Mohammedan faith, or to pay the usual tribute exacted from unbelievers. " If you refuse," said he, " you will have to contend with people who love the taste of death more than you love wine and swine's flesh, and rest assured that I will come up against you, and will not depart until I have slain all the able-bodied men among you, and carried off your women and children captive." To this message a decisive refusal was returned, and Abu Obeidah, in accordance with his threat, marched upon Jerusalem and besieged the town. The Christians, after several unsuccessful sallies, finding themselves reduced to great straits by the protracted siege, made overtures for capitulation, but refused to treat with any but the caliph himself. Having exacted a solemn oath from them that they would hold to the proposed conditions in case of his sovereign's arrival; the general sent a message to Omar, inviting him to leave Medina, and receive in person the capitulation of the.town. The messengers from Abu 'Obeidah's camp were accompanied by some representatives of the Christian community, and the latter were much astonished at the stern simplicity and comparative retirement in which the caliph was