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1202 CEReputable source · 2 sourcesWell documented

Fibonacci Publishes Liber Abaci and Brings Hindu-Arabic Numerals to Europe

A merchant's son educated in North Africa introduces the numeral system the whole world uses today, wrapped around a puzzle about rabbits

On the timeline · around 1202 CE · Medieval and Islamic MathematicsMedieval and Islamic MathematicsThe Scientific RevolutionFibonacci Publishes Liber Abaci and Brings Hindu-Arabic Numerals to Europe900 CE10001100120013001400

Quick facts

Fibonacci's dates
c. 1170 to c. 1250
Liber Abaci published
1202 CE
Educated in
Bugia, North Africa (modern Bejaia, Algeria)
Sequence introduced
1, 1, 2, 3, 5, 8, 13, 21, 34, 55...

What happened

Leonardo of Pisa, known as Fibonacci, was born around 1170 in Pisa but educated in North Africa, where his father Guilielmo held a diplomatic post representing Pisan merchants in Bugia, in modern Algeria. There Fibonacci learned mathematics and traveled widely with his father, encountering the Hindu-Arabic numeral system already established across the Islamic world since al-Khwarizmi's time. In 1202 Fibonacci published Liber Abaci, which introduced the Hindu-Arabic place-valued decimal system and Arabic numerals to a European audience still using Roman numerals for calculation. The book also poses a problem about a pair of rabbits that produces a new breeding pair every month starting from their second month, generating the sequence 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 and onward, which later became known as the Fibonacci sequence.

Why it matters

Liber Abaci is the book credited with starting the slow, centuries-long process of replacing Roman numerals with the Hindu-Arabic decimal system across Europe, the number system still used worldwide today for everything from arithmetic to computing. The rabbit sequence buried inside a merchant's arithmetic manual would later turn out to describe patterns across biology, art, and mathematics far beyond its original purpose.

How we know

Liber Abaci survives in Latin manuscript, and Fibonacci's own account of his education in Bugia under his father's diplomatic posting is recorded in the book's prologue, giving a documented route by which Hindu-Arabic numerals and Islamic mathematical practice reached him directly.

Sources

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Part of a timelineHistory of Mathematics26 events · A number system built for taxes, a theorem older than the man it's named for, a proof too long for a margin, and an infinity too big to countView all →