The Traditional History
I will give the predominate traditional history of Islam as taught to everyone until about the last decade. This history is based upon retrospective (once upon a time) historical documents since there is no real time documents. In other words, we do not know about Islam because of written testimony of people who lived this history, or eyewitness accounts of the events. Compared to Christianity, it is a legend. Two real time historians, Josephus and Tacitus both mentioned the existence of Jesus, but no historian during the time of Muhammad told of his existence or the existence of Mecca.

Muhammad was supposedly born in Mecca in 570 AD. Muhammad, an orphan, was raised by his grandparents and uncle, Abu Talib. He then traveled with his uncle who was a trader, and Muhammad would later become a trader himself. At age 25, he then married Khadija, a wealthy 40-year-old woman. It is said she had more camels (wealth inherited from her father) than all of her whole tribe combined. Muhammad, wanting to add even more to his wealth, became a prolific caravan raider.

Muhammad had his first of over 100 private visions in a cave in 607. He spoke only to the angel Gabriel since Muhamad said God does not speak to humans. Muhammad thought he was crazy and told his visions to his wife. She convinced him he was speaking to an angel, and he was a unique prophet. Muhammad went on to have at least 10 more wives. One wife was Aisha, a 6-year-old girl. Mohammad, who was over 50, waited until she was 9 before having sex with her. Muhammad wrote in the Koran that men should not have more than 4 wives, although a prophet could have many more.

Muhammad wrote the Koran cover from 610 and 632. Muhammad’s first visions happened while he was in Mecca, but he concluded his visions while he was in Medina. Actually, Muhammad did not write the Koran, since he admits being illiterate. It is believed Muhammad’s secretary, Abu Bakr, wrote the Koran after collecting and burning about 100 other written copies he and Caliph Uthman considered incorrect. Legend says Bakr did this about 2 years after Muhammad’s death. However, no copy of a complete Koran exists until almost 200 years later.

Muhamad Is claimed to be a direct descendant of Ishmael. This excludes him from receiving the everlasting covenant of the Bible and being a great prophet. About Isaac the Torah, states, “Then God said, "Yes, but your wife Sarah will bear you a son, and you will call him Isaac. I will establish my covenant with him as an everlasting covenant for his descendants after him. But my covenant I will establish with Isaac, whom Sarah will bear to you by this time next year" (Gen 17:19,21 NIV) About Ishmael it says; “And as for Ishmael, I have heard you: I will surely bless him; I will make him fruitful and will greatly increase his numbers. He will be the father of twelve rulers, and I will make him into a great nation. (Gen 17:20 NIV) “He will be a wild donkey of a man; his hand will be against everyone and everyone's hand against him, and he will live in hostility toward all his brothers" (Gen 16:12 NIV). So, we read, Ismael’s descendants will be a great nation, but they will not be God’s chosen people. Consequently, it is implied in the Koran (and believed by Muslims) that Ishmael, not Isaac, was put on the alter and received the blessing.

After Muhammad’s death, there was a violent power struggle for his successor. The Sunni claimed Muhammad did not appoint a successor, and elected Muhammad’s father in-law, Abu Bakr, as the leader. Shia believed Muhammad had selected his cousin/son-in-law, Ali Ibn Abi Talib, as their leader. Thus, there were numerous battles between these two factions, and 3 of the first 4 Caliphs were assassinated. So much for the supposed “religion of peace.” This should be no surprise to anyone who reads the Koran.
By 1000 AD, Muslim aggression has conquered much of Arabia, Asia, southern Europe, and northern Africa. When Muslims denied access to Jerusalem by Christians and Jews, the Crusades began in 1090 to halt Muslim aggression. So, one can see that the Crusades was a defensive initiative, not an offensive one. Moreover, Muslim violent theocracy can be traced back to the Koran, which is covered in another lesson.

Newly Discovered History
Recent archeological discoveries and scholastic review have a whole different story. There seems to be conclusive evidence the Koran was actually first written almost 200 years after the supposed birth of Muhammad, and the whole story of Muhammad and Mecca were completely made up. The proof for this theory is so extensive it is impossible for me to do a thorough Job explaining it. The most enjoyable, but comprehensive explanations of this widely accepted theory are given by world acclaimed Dr. Jay Smith who has well over 100 YouTube videos bringing together the works of many scholars. Links to his best videos are as follows:

1. New research on Islam - https://www.youtube.com/watch?v=6QpSG87CtPE&t=31s

2. Beginning of Islam - https://www.youtube.com/watch?v=jorBwia9yFw&t=71s

3. History of mosques - https://www.youtube.com/watch?v=0ZKcpDEEJnA&t=1278s

4. History of Koran - https://www.youtube.com/watch?v=3nXzi-_WTdI&t=2s