Timeline of Islam and Muhammad
570 C.E. Muhammad is born in Mecca into a noble family. He earns the reputation of being an honest and reliable person
610 According to Muslim belief, at the age of 40, Muhammad is visited by the angel Gabriel while on retreat in a cave near Mecca. The angel recites to him the first revelations of the Quran and informs him that he is God's prophet. Later, Muhammad is told to call his people to the worship of the one God, but they react with hostility and begin to persecute him and his followers.
622 After enduring persecution in Mecca, Muhammad and his followers move to Medina, which at the time was known as Yathrib. The people here accept the Islamic faith, signifying the "hijrah" or "emigration," and the beginning of the Islamic calendar. In Medina, Muhammad establishes an Islamic state based on the Quran and the guidance of God. Eventually he begins to invite other tribes and nations to Islam.
630 Muhammad returns to Mecca with a large number of his followers. He manages to enter the city and eventually he and Islam are accepted. Muhammad clears out the Kaaba and rededicates it to the worship of God.
633 Muhammad dies after a prolonged illness. The Muslim community elects his father-in-law and close associate, Abu Bakr, as caliph, or successor.
638 Muslims enter the area north of Arabia, known as "Sham," including Syria, Palestine, Lebanon and Iraq.
641 Muslims enter Egypt and destroy Byzantine army, freeing those who were under oppressive ruling, similar to the Hebrews and Egypt and the story of Moses in the Old Testament.
655 Islam begins to spread throughout North Africa.
661 Imam Ali is killed, bringing to an end the rule of the four "righteous caliphs": Abu Bakr, Umar, Uthman, and Ali. This also marks the beginning of the Umayyad rule.
711 Muslims enter Spain in the west and India in the east, bringing almost all of the Iberian Peninsula under Islamic rule.
732 Charles Martel defeats the Muslims in France.
750 The Abbasids take over rule from the Umayyads, shifting the seat of power to Baghdad.
1000 Islam continues its spread across the world to Africa.
1099 European/Christian Crusaders take Jerusalem from the Muslims, but the Muslims regain control of Jerusalem later on.
1120. Islam spreads to Asia through Malaysian traders with the Muslims.
In my opinion, the most important event in Islamic history comes after the death of Muhammad, and actually with the death of Iman Ali. After the Umayyad rule began, Islam became more aggressive with their expansion and began to reach across more continents and possess more of those continents. Without this change in mentality, Islam may still have been a minor religion today and not have gained the massive following by spreading its message throughout the Eastern Hemisphere.