In 750 AD, it seemed like the Islamic Empire would last a thousand years. The Abbasid caliphs ruled a giant empire. It stretched from Morocco to Afghanistan. Their capital was at Baghdad in modern Iraq. Baghdad was also a center of scholarship and trade. The Abbasids kept control until the early 900s – that’s a run of more than two hundred years, which isn’t bad for an empire. But then the empire split into two caliphates (KAL-if-fates). First the Fatimid dynasty took over all the Islamic land that had once been in the Roman Empire: Egypt, North Africa, Israel and Syria, and the Arabian Peninsula. The Abbasids still ruled the half that had once been the Sassanian Empire.
Then a second change began, possibly because of some sort of climate change. Turkish and Mongol people from Central Asia started to migrate south and west into both of these Islamic Empires. The Ghaznavids and the Seljuks – both Turkish groups – first came into the Abbasid empire as mercenary soldiers. But in 962 AD, the Ghaznavids made Afghanistan and Pakistan an independent country under their rule. Then just after 1000 AD, the Seljuks also decided to rule for themselves. The Seljuks conquered the Ghaznavids. By 1055 they also took over Baghdad. And in 1071 they conquered Turkey from the Byzantines at the Battle of Manzikert. Because of their start in Iran, the Seljuks spoke Persian, rather than Arabic or Turkish.
The Islamic Empire’s weakness invited other raiders in. In 1096 AD, European Crusaders conquered a good deal of Israel and Lebanon from the Fatimids and plundered it. By 1200, two more Turkish groups, the Ayyubids (under Saladin) and the Mamluks, took Israel back from the Europeans. But more pieces broke away. The Almohads succeeded in forming an empire out of North Africa and Spain.
During the 1200s, the Almohad empire in turn broke apart into even smaller pieces. In northern Spain, the kingdoms of Aragon, Castile, and Portugal defeated the Almohads in 1212, and conquered most of Spain by 1248 AD. In North Africa, the Almohad empire also split into three smaller kingdoms: the Hafsids in the east, the al-Wadids in the center, and the Marinids in the west. Then in the 1300s and 1400s, the armies of Aragon and Castile gradually forced the Almohads and then the Nasrids out of Spain, finishing up in 1492 AD.
Back in the eastern part of the Islamic Empire, the Mongols invaded in 1260 AD – were they driven by the beginning of the Little Ice Age? – and conquered it from the Seljuks. The Mongols created another huge empire, but this one had different borders. It covered the old Sassanian Empire and Turkey, but also most of Central Asia, Pakistan, part of northern India, and China. The Mongols held their empire together for almost a hundred years, until the Black Death caused a collapse in the 1340s AD. Even after that, the Mongol Timur rebuilt part of the Mongol Empire. Timur (or Tamerlane) ruled from Turkey all the way across Russia to Afghanistan and northern India. But Timur’s empire collapsed when he died in 1405 AD.
In the 1400s, the Ottomans (successors to the Seljuks) began to build themselves a third big Islamic Empire. Like the Fatimids, the Ottomans focused on taking over the Roman half of the Islamic Empire. The Ottomans took Constantinople (modern Istanbul), Greece, and Eastern Europe from the Byzantines in 1453 AD. In 1464, they conquered the Marinids in Morocco. Then in 1517, they conquered Syria, Israel, and Egypt. And in 1574, the Ottomans conquered the Hafsids in North Africa. So in these 800 years several big empires rose and fell, but in the end, most of the Islamic world was still united.