The mathematician originally known as Leonardo Pisano Bigollo was born in Italy, around the year 1170. His father was a prosperous merchant, and Fibonacci often accompanied him on his travels to northern Africa. There he witnessed the use of Hindu-Arabic numerals (digits like 0,1,2,3, etc.). He realized they were much more practical than Roman Numerals. He used this finding to assist him in his various mathematical pursuits. In 1202, he published Liber Abaci (Book of Calculation). This spread Hindu-Arabic numerals to the Western World. He used examples such as the Fibonacci Sequence to demonstrate their importance. Fibonacci was well respected for his contribution in mathematics and was a frequent guest of the Holy Roman Emperor, Frederick II. He died in Pisa Italy c. 1250.