After Muhammad died, the people who lived with him and knew his religion best immediately fell into war with each other. Fatima, Muhammad's favorite daughter, survived the early years among the unbelievers at Mecca safe and sound, yet died of stress from the persecution of fellow Muslims only six months after her father died. She even miscarried Muhammad's grandchild after having her ribs broken by the man who became the second caliph. Fatima's husband Ali, who was the second convert to Islam and was raised like a son to Muhammad, fought a civil war against an army raised by Aisha, Muhammad's favorite wife - and one whom he had said was a "perfect woman." 10,000 Muslims were killed in a single battle waged less than 25 years after Muhammad's death. Three of the first four Muslim rulers (caliphs) were murdered. All of them were among Muhammad's closest companions. The third caliph was killed by allies of the son of the first (who was murdered by the fifth caliph a few years later, then wrapped in the skin of a dead donkey and burned). The fourth caliph (Ali) was stabbed to death after a bitter dispute with the fifth. The fifth caliph went on to poison one of Muhammad's two favorite grandsons. The other grandson was later beheaded by the sixth caliph. The infighting and power struggles between Muhammad's family members, closest companions and their children only intensified with time. Within 50 short years of Muhammad's death, even the Kaaba, which had stood for centuries under pagan religion, lay in ruins from internal Muslim war. And that's just the fate of those within the house of Islam! From the beginning, Islam conquered and bullied its way into control of the Middle and Near East. To be sure, the Roman Empire and their successors in the eastern Mediterranean, the Byzantines, were equally capable of foisting their brand of "Christianity" upon then pagan peoples or even other Christians with different beliefs, but Islam has kept it up into the modern era. Its monopolistic view of human religious belief has resulted in a mass cultural genocide and a most pesty tendency toward one sided fanaticism. It is not a healthy legacy. The early split between Shia and Sunni is a simmering Gog and Magog which lurks behind many of the tensions in the Middle East. While i will defer to Muslims as to their sincerity of belief, i do wonder whether Mohammed did not envision the power of a religious ideology as a way of dealing with the encroachments of Byzantine Christianity all around the Mediterranean. Only by uniting Arabs and other local peoples under the banner of a single new religion could they form a group strong enough to take on the this last vestige of the Roman Empire which had ruled the area to varying degrees since before the birth of Jesus some seven hundred years before. Add that to the fact that the Roman Empire was dead and the Byzantine Empire, in fact, was corrupt, ageing and vulnerable, Arab growth grew quickly throughout former Byzantine lands and into Europe proper. Building one of their greatest Holy Sites upon the temple walls of the city most sacred to Jews and Christians created a lasting sore point if, also, an intended reminder that Islam is the equal, if not greater, than either Judaism or Christianity - a crown jewel of military and religious triumph. The Ottomans did the same with the world renowned Byzantine Christian Basilica, Hagia Sophia, when they turned it into an imperial mosque.