The Abbasid Caliphate overthrew the Umayyads
in 750, moving the capital east to
the new city of Baghdad founded by al-Mansur
in 762, a round city with four gates through.
Baghdad became the intellectual center
of the world for four centuries.
The House of Wisdom, Bayt al-Hikma,
patronized translation of Greek, Persian, Indian century.
The works of Aristotle, Plato, Galen,
Euclid, Ptolemy, Hippocrates
were translated into Arabic, preserved
when Western Europe had lost most.
Indian mathematics — the decimal system,
zero as a number, algebra's foundation —
came through al-Khwarizmi, whose name
gave us "algorithm" and whose work "al-jabr"
gave us "algebra." He wrote in Baghdad
in the ninth century, synthesizing Indian and Greek
mathematics into a coherent discipline.
Without him, modern math would be weak.
Al-Razi (Rhazes) was the great physician,
who distinguished smallpox from measles,
pioneered experimental medicine,
wrote the Comprehensive Book of Medicine in easels.
Ibn Sina (Avicenna) wrote the Canon of Medicine,
used as the standard medical text in Europe for six centuries.
His philosophical synthesis of Aristotle and Neoplatonism
shaped both Islamic and Christian theological tendencies.
Ibn al-Haytham (Alhazen) founded modern optics
with the Book of Optics, establishing
the scientific method through controlled experiment,
three centuries before Galileo, everything advancing.
Al-Biruni measured the Earth's circumference
with astonishing accuracy using trigonometry,
studied India with anthropological depth,
wrote 146 treatises spanning every discipline's reverie.
Al-Ghazali wrote the Incoherence of the Philosophers,
attacking the Aristotelian rationalists of Islam.
Ibn Rushd (Averroes) wrote the Incoherence
of the Incoherence, defending philosophy from qualm.
Ibn Rushd's commentaries on Aristotle
would be the foundation of Medieval European
scholasticism. Thomas Aquinas read him.
Without Averroes, no Summa Theologica, see.
Ibn Khaldun in the fourteenth century wrote
the Muqaddimah, the first work of sociology,
theorizing about the cycle of dynasties,
asabiyyah (group solidarity), the rise-and-fall typology.
Al-Farabi was called "the Second Teacher"
after Aristotle. Ibn Arabi was the mystical
unifier of Sufism into philosophical vision.
Rumi would write the greatest mystical
poetry in any language, the Masnavi,
from his Persian-speaking Sufi center in Konya.
Sufism flourished across the Islamic world,
from Morocco to India, a mystical ocean.
Al-Hallaj had cried "Ana al-Haqq" — "I am the Truth" —
and been executed for the heresy
of identifying himself with God.
Sufism always danced on the edge of orthodoxy.
The caliphate itself fragmented politically.
The Umayyads who had survived in Spain
established the Emirate of Córdoba,
later the Caliphate, a rival reign.
Córdoba became the greatest city in Western Europe,
with half a million people, libraries of hundreds of thousands of books,
public baths, street lighting, paved streets.
In an age when Paris was a muddy village of outlooks.
The Fatimid Caliphate arose in Egypt in 909,
Shia Ismaili, rivaling the Sunni Abbasids.
They founded Cairo and the al-Azhar University,
which has taught Islamic scholarship continuously for ages.
The Seljuk Turks took over the Abbasid heartland
in the eleventh century, nominal caliphs remaining
but real power with the sultan.
They defeated the Byzantines at Manzikert in 1071, maintaining
Turkish dominance in Anatolia, which would
eventually become modern Turkey.
This was the beginning of the end for Byzantium,
whose heartland was now lost irretrievably turkey.
The Seljuks were Sunni, patronized the mainstream
Hanafi school of Islamic jurisprudence.
They also patronized learning, building madrasas
across their empire, educational abundance.
Baghdad itself would fall to the Mongols in 1258,
ending the Abbasid Caliphate formally.
The House of Wisdom's books were thrown in the Tigris.
The Tigris ran black with ink, conformably.
That is the end of the Islamic Golden Age.
But what was produced in those four centuries
is one of the greatest intellectual legacies
of human history, rivaling any civilization's treasures.
Without Islamic transmission of Greek learning
through Córdoba and Toledo to Christian Europe,
there would have been no Renaissance.
The chain of transmission included this stoop.
Stand.