A narration in the most authoritative of the Hadith books, Saheeh al-Bukhari, told Auf bin Malik to look for six incidents before the last day: "The first,my death; the second the conquest of Jerusalem; third, an epidemic among them; fourth, the abundance of wealth so that a man would not gladly accept one hundred dinars even if given it; fifth, a trouble that would involve all Arab families without exception; sixth, a treaty with the Christians, which the Christians would violate, etc.. (the hadeeth describes this last event, not yet fulfilled). Jerusalem was captured, and after this in 16 A.H. an epidemic broke out in Umwas and seventy thousand died. Wealth became plentiful, especially during the Caliphate of 'Uthman, and after that in the time of 'Umar ibn AbdulAzziz, when the collectors of zakat found no one poor enough to receive it. Also the rebellious war arose in the time of Uthman and became worse after his murder, so none of the Arabs families were not involved in some respect.
The Prophet mentioned that the Muslims would conquer both Rome and Constantinople. He was asked which would fall first, and the Prophet said: "The city of Heraclius", i.e. Constantinople(Istanbul). Constantinople was taken by the Muslims in the fifteenth century. Rome still remains to be conquered, as it will be. So the order is correct, and rest still to be fulfilled.
