Daily History Challenge · No. 9 · Tuesday 7 July 2026 · Chain

Puzzle No. 9: Chain

The anchor was Al-Khwarizmi composes Al-Jabr and founds algebra (813 CE). Every challenger is listed below with its year.

The anchor

c. 820 CEAl-Khwarizmi composes Al-Jabr and founds algebra

Working at the House of Wisdom in Baghdad under the caliph al-Ma'mun, the Persian scholar Muhammad ibn Musa al-Khwarizmi compiled, around 820, his treatise Al-Kitab al-mukhtasar fi hisab al-jabr wa-l-muqabala (The Compendious Book on Calculation by Completion and Balancing). It presented the first systematic method for solving linear and quadratic equations as a discipline in its own right, independent of geometry, and gave the world the word algebra, from al-jabr. In a separate work al-Khwarizmi explained the Hindu-Arabic decimal place-value system and the use of zero; the Latinised form of his name yielded the term algorithm. The House of Wisdom, which flourished as a translation centre and research academy under al-Ma'mun, brought Greek, Persian and Indian mathematics and astronomy into Arabic, and al-Khwarizmi's syntheses became foundational. Translated into Latin in twelfth-century Spain, his works transmitted both algebra and the numeral system to medieval Europe, reshaping commerce, science and mathematics. Al-Khwarizmi is consequently remembered as a father of algebra and one of the central figures of the Islamic Golden Age.

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