Born in Pisa in 1170 (probably) and died in 1250 (possibly), L Fibonacci was better known at the time under the name Leonardo Pisano (Leonard of Pisa) or Leonardo Bigollo (negative term meaning ‘ wandering good-for-nothing’). His modern-day name came from his father, Guilielmo Bonacci (hence Fibonacci: ‘Son of Bonacci’) who occupied a diplomatic post in North Africa during the boyhood of the future mathematician.
Until 1200, Fibonacci supposedly travelled around the Mediterranean acquiring his knowledge of mathematics in Egypt, Syria, Greece, in Sicily, and in Provence (as mentioned in the Liber Abacci of 1202).
The Abacci Liber (concerning abacuses, the ancestors of modern computers and cousins of the Chinese counting frames) was the first of several mathematical works :
Pratica Geometriae (1220), Flos (1225), Liber quadratorum ( 1225), and Di Minor Guisa, of which there remains no manuscript (it should be remembered that all that occured at least two centuries before Gutenberg!).
Fibonacci is best known for the number series which carries his name (1,1,2,3,5,8,13,21,34,55…), but it is worth knowing that it is to him that we owe the systematic introduction of the Hindu-Arabic decimal system to Europe; however, he was more famous in his time for the practical applications his methods offered merchants in the exercise of their trade.
From the 1230’s until the end of his life, we have little information about Fibonacci; a text of 1240 states that a sum of money was granted to him by the state of Pisa, in return for services rendered to the town; we know nothing of the last years of this great visionary.