He is also known as Leonardo Fibonacci and lived from 1170 to 1250. He is known to be one of the greatest mathematicians of the Middle Age. He came up with the Fibonacci Series and he contributed a lot to the Arabic numbering system. He came back to Italy from the Arabic world in 1202 and came up with Liber Abaci where he tried to introduce the Arabic numbers in many situations because he considered them to be easier and much less complex than the roman numerals. He is considered to be great asset in the development of modern mathematics.