Leonardo Bonacci (c. 1170 – c. 1250) - known as Fibonacci (Italian: \[fiboˈnattʃi\]), and Leonardo of Pisa, Leonardo Pisano Bigollo, Leonardo Fibonacci—was an Italian mathematician, considered to be "the most talented Western mathematician of the Middle Ages". Fibonacci popularized the Hindu–Arabic numeral system to the Western World primarily through his composition in 1202 of Liber Abaci (Book of Calculation). He also introduced to Europe the sequence of Fibonacci numbers which he used as an example in Liber Abaci. Fibonacci was born around 1170 to Guglielmo Bonacci, a wealthy Italian merchant and, by some accounts, the consul for Pisa. Guglielmo directed a trading post in Bugia, a port in the Almohad dynasty's sultanate in North Africa. Fibonacci travelled with him as a young boy, and it was in Bugia (now Béjaïa, Algeria) that he learned about the Hindu–Arabic numeral system.
Fibonacci travelled extensively around the Mediterranean coast, meeting with many merchants and learning of their systems of doing arithmetic. He soon realised the many advantages of the Hindu-Arabic system. In 1202 he completed the Liber Abaci (Book of Abacus or Book of Calculation) which popularized Hindu–Arabic numerals in Europe.
Fibonacci became a guest of Emperor Frederick II, who enjoyed mathematics and science. In 1240 the Republic of Pisa honored Fibonacci (referred to as Leonardo Bigollo) by granting him a salary.
The date of Fibonacci's death is not known, but it has been estimated to be between 1240 and 1250, most likely in Pisa.....