From 12th Century Italy to the Da Vinci Code--Who was Fibonacci?

He was variously known as Leonardo of Pisa, Leonardo Bonacci or as most people today call him, Fibonacci (fib-oh-NOTCH-ee). The year of his birth is not known with certainty but is pegged at around 1170 which places him in the time we know as the Middle Ages or Medieval period. If you read Dan Brown's popular novel, the Da Vinci Code, you know that the sequence of numbers-1, 1, 2, 3, 5, 8, 13 and so on-in which each succeeding number is the sum of the preceding two, is known as a Fibonacci series. This series figures very importantly in the story, but who was Fibonacci and how did he come by this interesting mathematical discovery?

Leonardo's father, Guglielmo Bonacci, was an official in the customs house of Bugia, a port city in Algeria where Pisa had established a trading center with the Moors. In 1192, Bonacci brought his son to Bugia probably with the intention of having him learn the trade of merchant. Leonardo was taught the Arabic system of calculation by the Moors and he quickly saw its value over the cumbersome Roman numerals. The Arabic numbers were 1 to 9 plus the all-important 0 as place indicator. Leonardo traveled with his father to many cities in Syria, Egypt, Greece and the Middle East where he learned much more about mathematics and doubtless about life as well.