c. 1170-c. 1250

Italian Mathematician

Atowering figure in the history of mathematics—to say nothing of mathematical studies during the medieval period—Leonardo Pisano Fibonacci is credited with the introduction of the Hindu-Arabic numeral system to Europe. He is also remembered for the Fibonacci sequence, whose recursive quality has made it a continued subject of fascination for mathematicians.

The dates of Fibonacci's life are uncertain, and his name itself presents something of a challenge. He was born in Pisa, and thus is sometimes known as Leonard of Pisa. His father was William or Guillermo Bonacci, and the name Fibonacci appears to be a contraction meaning family of Bonacci, or son of Bonacci. Thus the mathematician became known to history by his given name, that of his city, and the contraction: Leonardo Pisano Fibonacci.

Pisa at that time was a great trading center, and when Fibonacci...