Mind-Benders of Islamic History
All true, and all a little hard to believe — collisions of time, science, and discovery from a thousand years of the Islamic world.
Deep timeThe Cairo doctor who described the lungs' circulation 300 years early
Around 1242 CE, the physician Ibn al-Nafis, working in Cairo, described how blood passes from the right side of the heart through the lungs before returning to the left side — the pulmonary circulation. He set this down in his commentary on the anatomy of Ibn Sina's Canon, more than three centuries before the English physician William Harvey (1578–1657) published his own account of the circulation in his 1628 De Motu Cordis. The Arabic manuscript only resurfaced in the 20th century.
How we know
Ibn al-Nafis (c. 1213–1288), Commentary on the Anatomy of the Canon of Avicenna c. 1242 CE (manuscript rediscovered 1924); William Harvey (1578–1657), De Motu Cordis, 1628. Gap: 1628 − 1242 = 386 years.
A surgery textbook Europe leaned on for 500 years
Around the year 1000, the Andalusian physician al-Zahrawi completed 'al-Tasrif,' a thirty-volume medical encyclopedia. Its surgical section — illustrating roughly 200 instruments and describing techniques such as catgut for internal stitches — was translated into Latin (by Gerard of Cremona in the late 12th century) and served as a standard reference in European medical schools for roughly five hundred years.
How we know
al-Zahrawi (Abulcasis), c. 936–1013; Kitab al-Tasrif completed c. 1000 (30 vols, ~200 surgical instruments described); Latin translation by Gerard of Cremona late 12th c.; standard European surgical text into the 16th c. (Wikipedia: al-Zahrawi / Al-Tasrif).
Two everyday math words are one man's name and his book title
Around 820 CE the Baghdad scholar al-Khwarizmi wrote a treatise whose Arabic title contained the word "al-jabr" — the root of our word "algebra." When his works were later rendered into Latin, his own name was Latinized as "Algoritmi," which is where the word "algorithm" comes from. Both terms are still in daily use roughly 1,200 years later.
How we know
al-Khwarizmi (c. 780 – c. 850 CE); Al-Jabr (al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa'l-muqābala) written c. 820 CE at Baghdad's House of Wisdom; "algebra" from "al-jabr" (Robert of Chester's 1145 Latin translation), "algorithm" from his Latinized name "Algoritmi."
He built optics on experiment, in a Cairo dark room
Ibn al-Haytham (c. 965–1040), writing his Book of Optics in Cairo around 1011–1021, argued that vision results from light entering the eye and gave one of the first clear descriptions of the camera obscura, the darkened chamber that projects an inverted image through a small hole. Translated into Latin as De aspectibus, his work later informed European students of light including Johannes Kepler (1571–1630).
How we know
Ibn al-Haytham b. c.965 Basra, d. c.1040/1041 Cairo; Kitāb al-Manāẓir (Book of Optics) written in Cairo c.1011–1021; intromission theory + dark-room (al-bayt al-muẓlim) camera-obscura description; Latin De aspectibus (late 12th–early 13th c.) influenced Bacon, Witelo, Kepler (1571–1630, optical work c.1604).
The prince who charted the stars — and was killed by his own son
Ulugh Beg (1394–1449), a grandson of the conqueror Timur, ruled Samarkand but gave his passion to astronomy, building one of the medieval world's greatest observatories. In 1437 he completed a star catalogue fixing the positions of more than a thousand stars with remarkable precision, and in 1449 he was deposed and put to death on the order of his own eldest son — just four years before the fall of Constantinople in 1453.
How we know
Ulugh Beg b. 22 Mar 1394, d. 27 Oct 1449 (beheaded on order of eldest son Abd al-Latif); Zij-i Sultani star catalogue completed 1437, lists 1,018 stars (992 newly observed); grandfather Timur d. 1405; Constantinople fell 1453 (1453−1449 = 4 yrs).
Pi to sixteen decimals, by hand, in 1424
The Persian mathematician al-Kashi (c. 1380–1429), working at Samarkand, computed pi to an accuracy equivalent to sixteen decimal places in his Treatise on the Circumference (1424). It was the most precise value known anywhere, and it held the record for roughly 170 years, until Ludolph van Ceulen surpassed it in 1596.
How we know
Jamshīd al-Kāshī (b. c.1380 Kashan – d. 22 June 1429 Samarkand); Risāla al-muḥīṭiyya (Treatise on the Circumference), July 1424, π to ~16 decimal digits via a 3×2^28-sided polygon; unsurpassed until van Ceulen's 20 digits in 1596 (172 yrs). Refs: Britannica, MacTutor (St Andrews), Wikipedia.
The star professor who walked away from the top post
In 1091, at about 33, al-Ghazali (1058–1111) was appointed to one of the most prestigious teaching chairs in the Islamic world, at the Nizamiyya college of Baghdad. Roughly four years later a personal crisis left him, by his own account, unable to lecture; he gave up the post, parted with much of his wealth, and spent about a decade wandering and in seclusion before returning to teaching. He described the ordeal in an autobiography, "Deliverance from Error" (al-Munqidh min al-Dalal).
How we know
al-Ghazali b. 1058 – d. 1111; appointed Nizamiyya of Baghdad July 1091 (age ~33); left amid a crisis 1095; resumed teaching (Nizamiyya of Nishapur) c. 1106; autobiography al-Munqidh min al-Dalal ("Deliverance from Error").
More than thirty years on a single poem
The Persian poet Firdawsi (c. 940–1020) spent more than three decades — from about 977 to its completion in 1010 — composing the Shahnameh ("Book of Kings"), an epic of roughly 50,000 rhymed couplets and one of the longest poems ever written by a single author.
How we know
Firdawsi (Ferdowsi) c. 940–1020 CE; composed the Shahnameh c. 977–1010 (completed 8 March 1010), ~33 years; ~50,000 couplets, longest poem by a single author (Britannica; Encyclopaedia Iranica; Wikipedia).
The scholar who wrote on everything — and learned Sanskrit to do it
The polymath al-Biruni (973–1048) is credited with some 146 works spanning astronomy, mathematics, geography, mineralogy, pharmacology and history, and he learned Sanskrit to research a detailed study of India. Using trigonometry and observations from a mountaintop, he estimated the Earth's radius at about 6,340 km — within roughly 1% of the modern figure of 6,371 km.
How we know
Abū Rayḥān al-Biruni, b. 973 (Kath, Khwarezm) – d. 1048 (Ghazna); 146 attributed titles; Earth-radius result ~6,339.6 km vs. modern mean 6,371 km (Britannica; MacTutor History of Mathematics; Encyclopaedia Iranica).
The philosopher of light, executed at 37
Al-Suhrawardi (c. 1154–1191) founded the "Illuminationist" (ishraqi) school of philosophy, built around metaphors of light. Accused of heterodox teachings, he was put to death in Aleppo in 1191 at about the age of 37 — during the years of the Third Crusade — a fate that earned him the lasting epithet "al-Maqtul," "the slain one."
How we know
Shihab al-Din al-Suhrawardi al-Maqtul: b. c.1154, executed Aleppo 1191 (587 AH), age ~37; founder of the Illuminationist/ishraqi school; execution ordered under the Ayyubids (al-Malik al-Zahir/Saladin). Third Crusade 1189–1192.
The prolific writer said to have been killed by his own books
Al-Jahiz (c. 776–869) was one of the most prolific prose authors of early Arabic literature, writing on zoology, rhetoric, theology and society, including his sprawling "Book of Animals." He lived into his nineties, and a long-standing tradition holds that he died when a stack of his own bound volumes toppled over and crushed him.
How we know
Al-Jahiz (Abu Uthman Amr ibn Bahr al-Kinani al-Basri), b. c. 776 in Basra, d. December 868 / January 869 (Muharram 255 AH) in Basra; manner of death uncertain (paralysis late in life; books-toppling story is a popular tradition).
A medical textbook that ruled European universities for 600 years
Ibn Sina (980–1037), known in Latin as Avicenna, was a physician and philosopher traditionally said to have qualified as a practicing doctor by about eighteen and to have written some 450 works. His Canon of Medicine, completed around 1025, was still a standard reference in European universities into the mid-1600s — roughly six centuries after he wrote it.
How we know
Ibn Sina/Avicenna b. 980 (near Bukhara) – d. 1037 (Hamadan); Canon of Medicine completed c. 1025; used in European universities (Padua, Bologna, Montpellier, Leuven) into the mid-1600s (c. 1650, some Italian schools to c. 1674) → ~600-625 yr span; ~450 works traditionally attributed (~240 survive).
The man who out-traveled Marco Polo
The Moroccan jurist Ibn Battuta left Tangier in 1325 — the year after Marco Polo died — and did not settle again for nearly three decades. By the time he dictated his travelogue, the Rihla, he had covered roughly 75,000 miles (about 120,000 km) from Timbuktu to the Maldives to the coast of China, a documented range no traveler of his era is known to have matched.
How we know
Ibn Battuta b. 24 Feb 1304, d. 1368/1369; departed Tangier 14 June 1325; traveled c.1325–1354 (≈29 yrs); ~117,000 km / ~73,000–75,000 mi (Ross Dunn). Marco Polo d. Jan 1324, ~24,000 km / ~15,000 mi.
A silver world map for a Christian king
Around 1154, the geographer al-Idrisi completed at the court of the Norman king Roger II of Sicily a book of world geography (the "Book of Roger") together with a large planisphere: a disc of silver reportedly some two metres across and weighing about 400 pounds, engraved with the seas, rivers and cities of the known world. He finished the work the same year Roger II died; the silver map was later broken up during civil unrest and lost.
How we know
al-Idrisi c.1100–1165; Book of Roger + silver planisphere (~400 Roman ratls, ≈2 m diameter) completed Jan 1154, weeks before Roger II of Sicily (b. 22 Dec 1095, d. 26 Feb 1154) died; map destroyed in unrest c. 1160.
Lowered by rope over a besieged city's wall to meet Tamerlane
In 1401, as the conqueror Timur (Tamerlane) besieged Damascus, the historian Ibn Khaldun — who had come with the Mamluk entourage and remained inside the city — had himself lowered over the wall by rope to meet him. The two conversed over several weeks, and Ibn Khaldun recorded the encounter in his own autobiography.
How we know
Ibn Khaldun (1332–1406) met Timur (c.1336–1405) during Timur's siege of Damascus, winter 1400–1401; the meetings spanned ~35 days in early 1401 and are recorded in Ibn Khaldun's autobiography (al-Taʿrīf); Fischel, "Ibn Khaldun and Tamerlane" (1952).
A mathematician in Baghdad while Charlemagne ruled Europe
Al-Khwarizmi — the Baghdad mathematician whose Latinized name gave English the word “algorithm” — was born around 780, while Charlemagne was building his empire across Europe (he was crowned emperor in 800). The Hindu-Arabic calculating methods al-Khwarizmi helped systematize would not take firm hold in Latin Europe until Leonardo of Pisa (Fibonacci) championed them in his Liber Abaci of 1202, nearly four centuries later.
How we know
al-Khwarizmi c.780–850 CE (algebra treatise compiled 813–833, Baghdad House of Wisdom); Charlemagne 748–814, crowned emperor 800; Fibonacci's Liber Abaci 1202. Overlap 780–814 = 34 yrs; 1202 − c.820 = 382 yrs (~4 centuries).
Three thinkers, one Spanish city
The philosopher Ibn Rushd (known in Latin Europe as Averroes) and the philosopher-physician Maimonides were born about twelve years apart in the same city, Córdoba, in the 12th century. A generation later, Thomas Aquinas, born 27 years after Ibn Rushd's death, engaged so closely with his Aristotle commentaries that Latin scholars called Ibn Rushd simply "the Commentator."
How we know
Ibn Rushd b. 1126 Córdoba, d. 1198; Maimonides b. 1138 (some sources 1135) Córdoba, d. 1204 (born ~12 yrs apart, same city); Thomas Aquinas b. 1225, d. 1274 (1225−1198 = 27 yrs after Ibn Rushd's death); scholastics titled Averroes "the Commentator."
An astronomer's numbers Copernicus was still using six centuries later
The astronomer al-Battani, observing from Raqqa around the year 900, measured the length of the solar year and the tilt of the ecliptic with striking precision. When Copernicus published De Revolutionibus in 1543, he cited al-Battani by name more than twenty times, still drawing on observations made over six centuries earlier.
How we know
al-Battani c. 858–929 CE (observations at Raqqa from 877); Copernicus's De Revolutionibus published 1543; al-Battani named ~23 times in it (Britannica; Wikipedia; De Revolutionibus text). 1543 − 929 = 614 years.
He built his observatory under the man who sacked Baghdad
The polymath Nasir al-Din al-Tusi (1201-1274) lived through the Mongol conquest of Baghdad in 1258. In the service of the Mongol ruler Hulagu Khan, he secured funding for a great observatory at Maragha, begun in 1259, which became one of the most advanced astronomical centers of its age.
How we know
Nasir al-Din al-Tusi 1201-1274; Mongol sack of Baghdad Feb 1258 (al-Tusi ~57); Maragha observatory construction begun 1259 under Hulagu Khan's patronage (MacTutor; Wikipedia, Maragheh observatory).
A 13th-century engineer built a machine you could reprogram
In 1206, the year of his death, al-Jazari completed "The Book of Knowledge of Ingenious Mechanical Devices," describing some fifty machines with step-by-step build instructions. Among them was a water-driven musical automaton whose drummer's rhythm could be changed by rearranging pegs — an arrangement often cited as an early example of a programmable machine.
How we know
Ismāʿīl ibn al-Razzāz al-Jazarī, c. 1136–1206; Kitāb fī maʿrifat al-ḥiyal al-handasiyya completed 1206, describing ~50 devices in six categories, incl. a musical-automaton boat with a peg/cam-programmable drummer (Donald R. Hill trans., 1974).
A calendar from 1079 keeps better time than ours
Omar Khayyam, better known today for his poetry, directed the commission of astronomers that produced the Persian Jalali solar calendar, inaugurated in 1079. Its scheme drifts from the true solar year by only about a day in several thousand years — a smaller error than the Gregorian calendar Europe adopted some 500 years later, in 1582.
How we know
Omar Khayyam (b. 18 May 1048, Nishapur – d. 4 Dec 1131); Jalali/Jalālī calendar inaugurated 15 March 1079 under Sultan Malik-Shah (Khayyam led the ~8-astronomer panel); accuracy ~1 day in ~5,000 years vs Gregorian ~1 day in ~3,330 years; Gregorian reform 1582 (1582−1079 = 503 years). Sources: Wikipedia (Omar Khayyam; Jalali calendar), MacTutor.
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