Detailed and easy to understand overview on "The Rise and Fall of Muslim Empires, 632-1920"

So it obviously begins with Muhammad. The interesting thing is that Muhammad was not just a spiritual leader (like Jesus) but a political one as well.

So it obviously begins with Muhammad. The interesting thing is that Muhammad was not just a spiritual leader (like Jesus) but a political one as well. You probably know the details of what he did and how he came to be the Prophet, but the short version is that he has some visions, starts preaching in his hometown of Mecca, royally pisses off the pagans, and is then driven along with his supporters. They flee to Medina for refuge, but the city of Mecca rallies an army to kill them. Muhammad unites the people of Medina through the Constitution of Medina, and he defeats the attacking Meccans at the Battle of the Trench and goes on to conquer Mecca. He then goes about uniting the various tribes of Arabia and bringing them under the banner of Islam.

Muhammad died in 632. A succession of the caliphate was not hereditary (yet), so the choice came down to Abu Bakr, who was elected by the tribes as the new caliph. Thus begins the Rashidun caliphate. It is important to understand the line of succession because it will later create the Sunni-Shiite split. Ali, Muhammad's cousin and son-in-law (it's complicated), was supported for the position by some of Muhammad's followers, but he bowed to the choice of Abu Bakr. The Rashidun started the Ridda Wars, which ultimately led to the conquest of Persia. They also managed to take Syria and Egypt from the Byzantines. The rapid conquest of these areas is largely due to how Muslims treated the 'Ahl al-Kitāb (Jews and Christians). Rather than persecute them, they were merely required to pay a special tax to support the caliphate, and otherwise they could worship and live in peace. This became time-tested Islamic doctrine throughout the Middle Ages, as proscribed by the Quran itself. These communities often faced less persecution under the Muslims than under the Persians and especially under the Byzantines. The Byzantines persecuted monophysites quite harshly while the Muslims did not, so many actively helped the foreign conquerors, allowing a speedy annexation of former Byzantine holdings.

All in all, the early Muslims were light rulers, which gained them a lot of respect and converts. Like most nomadic civilizations, they preferred to let the local people live as they pleased so long as they provided taxes and war materials.

The last of the Rashidun, Uthman, was assassinated after a rebellion flared up against him. Ali finally becomes caliph, but he is challenged by Muawiyah, the governor of Syria. Muawiyah was angered that Ali didn't want to persecute the rebels who killed Uthman, and thus began the First Fitna, or Islamic Civil War. This is officially where the Sunni-Shiite split occurs, with the Sunnis being the followers of Muawiyah and the Shiites being the followers of Ali. The two sides retreat to their respective capitals of Medina and Damascus. Ali gets killed in a mostly unrelated assassination, and his son offers terms to Muawiyah. Muawiyah would become caliph, but it would remain an elective body instead of hereditary. Muawiyah breaks the treaty anyways and the Umayyad dynasty is born.

Ali's sons basically all die in some way or another after they refuse to submit to Muawiyah. Meanwhile, the Umayyads continue to expand the caliphate, this time into Spain. Muawiyah and his successors change the make-up of the caliphate. They rule from Damascus, which alienates some of his subjects, and they raised taxes to pay for an unpopular set of wars. Plus, Muawiyah and many of his successors were just horrible, greedy, backstabbing dicks, but Sunni Muslims won't ever admit it because of the ongoing Sunni-Shiite stuff.

As far as interfaith relations, they were internally very good. Muawiyah was married to a Christian and many Jews and Christians served prominently in the administration. However, many Muslims despised the Umayyads for raising taxes and just being opulent in general. By the mid 8th century, the successors of the dynasty were basically killing each other all over the place for power during what is called the Third Fitna. They also managed to piss off various Arabic tribes. The tribal divisions of Arabia did not disappear with the creation of Islam, and biased decisions on the part of many caliphs only exacerbated them. Some of the later Umayyad rulers, like Yazid II, were less kind to the 'Ahl al-Kitab, while others were more sympathetic.

This turbulence and discontent caused the Abbasid Revolution. The Abbasid dynasty was based out of Persia. While being Sunnis, they still gained a lot of favor for being sympathetic to Shiites and 'Ahl al-Kitab, which helped propel the revolt forward. They stormed west and murdered almost all of the Umayyad family, with Abd ar-Rahman being one of the few to escape. ar-Rahman fled to Spain, where the Umayyads would remain in power for some time.

The Abbasids oversaw perhaps the first true Golden Age of Islam. The efficient, centralized administration of the Abbasids saw their caliphate flourish. Arts, sciences, and literature all expanded. There was a surprisingly modern hospital system throughout the caliphate. Baghdad became the new capital. Sufism became prominent during this time. It's really hard to describe Sufism or summarize it, since it is a massive topic in its own right, but basically it is a form of mysticism that is all about introspection and philosophy. Some Sufis of this era include Hasan al-Basri, Rabia, and Abu Yazid al-Bistami. For mainline Islam, this time saw the codification of the hadith, which are stories and anecdotes about Muhammad, under people like Al-Bukhari and Muslim, who validated and compiled hadith.

Oh, and the first university ever came into being under their reign. That's pretty important too.

Some important names of this time are Ibn Rushd and Ibn Sina, who were important philosophers.

All good things must end, however, and the Islamic Golden Age crept to a slow and undignified one The Abbasid caliphate gradually decentralized as religious and ethnic divisions took hold and the empire stagnated from a lack of expansion and the encroachment of foreign peoples, like the Turks. The concept of non-religious political dynasties that are only under the nominal rule of the caliph began to take hold. The caliphate began its spiral into irrelevance.

The Turks enter into Islamic history prominently around this time. Turks were commonly recruited as mercenary soldiers or captured as slaves to serve in the armies. They were widely regarded, like most Central Asian peoples, to be excellent fighters. Indeed, they were. The Seljuks split off from the other Turkish clans and moved west, eventually invaded the fractured caliphate and establishing a grand empire.

This is an excellent example of one of the reoccurring themes of Islamic history; nomadicism and sedentarism. The first Muslims started as nomads from Arabia, conquered Persia and Egypt, and then they gradually became sedentarized. Now, the Seljuks were the invading nomads, and they too would eventually sedentarize into several dynasties.

The Seljuks practiced a far more violent vision of Islam. It is under them that the term "jihad" becomes synonymous with "holy war". They were far less kind to Christians and Jews too, which is ostensibly what prompted the First Crusade (although political concerns played a primary role in that).

The Seljuks got embroiled in the Crusades against the Europeans, and this period really marks the decline of Islamic civilization. The Crusades are big, dumb, and expensive, causing gradual decentralization among the various states of the Seljuk Empire as support for the war drops. A new, pre-dominantly Shiite power rises as the Fatamid Caliphate. After them, Saladin becomes Sultan, finally establishing the precedent that a secular ruler can be just as powerful as a caliph. This is around the time of the Third Crusade.

Then the Mongols invade, and to summarize real quick like, shit gets real. The Mongols basically stomp the fuck out of Persia and Mesopotamia. They are successfully stopped by the Ayyubids, who later consequently find their empire usurped by the Mamlukes, a group of Turkish slave soldiers.

After the Mongol invasions, the Dar es Islam is basically in ruins. Baghdad was looted and pillaged. It's great libraries were turned out into the Tigris, where it is said that their ink made the river run black. The governor of the city was rolled into a carpet and the horses of the Mongol army trampled him to death. Millions were slaughtered. For a time, it was the deadliest military affair in human history, until the Siege of Leningrad during WWII.

I'm going to end it there for now since there is a lot to be said about the early modern period and I don't have the time or space.