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Primary sourceBookc. 820

Al-Jabr

Muḥammad ibn Musa al-Khwarizmi · c. 820

Al-Khwarizmi's treatise on algebra, written around 820, the first text to treat algebra as its own subject and the source of the word 'algebra'.

This is al-Khwarizmi's own treatise, the founding text of algebra and the source of its name.

Manuscript title page in Arabic script with a decorated gold-and-brown border. The large heading reads the title of al-Khwarizmi's algebra work, with smaller lines of text beneath in a calligraphic hand, on aged parchment.
Title page from a copy of al-Khwarizmi's Al-Jabr (The Concise Book of Calculation by Restoration and Balancing), c. 820.

About this source

What it is

Al-Jabr is an Arabic mathematical treatise written by al-Khwarizmi around 820 in Baghdad. It explains how to solve equations by 'restoring' (al-jabr) and 'balancing' (al-muqabala) terms, and also covers area, volume and inheritance calculations.

Why it matters

This book gave algebra its name and its first systematic treatment as an independent branch of mathematics. Translated into Latin in the twelfth century, it became the standard algebra textbook in European universities for centuries, showing how al-Khwarizmi's work under Caliph al-Ma'mun shaped mathematics far beyond Baghdad.

Look closer

  • Why do you think al-Khwarizmi wrote out equations in words instead of symbols?
  • What does the long section on inheritance tell you about why people needed algebra in his society?
  • How might a book written in Arabic have reached students in medieval Europe?

This book is part of the curated material that grounds the AI version of Al-Khwarizmi on Humy.ai — when students ask about related events, the AI can quote it and cite it.

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