Adelard of Bath
Adelard of Bath (; 1080 1152 AD) was a 12th-century English natural philosopher. He is known both for his original works and for translating many important Arabic and Greek scientific works of astrology, astronomy, philosophy and mathematics into Latin from Arabic versions, which were then introduced to Western Europe. He is known as one of the first to introduce the Arabic numeral system to Europe. He stands at the convergence of three intellectual schools: the traditional learning of French schools, the Greek culture of Southern Italy, and the Arabic science of the East.
Legacy of the Roman Empire
Roman numerals continued as the primary way of writing numbers in Europe until the 14th century, when they were largely replaced in common usage by Hindu-Arabic numerals. The Roman numeral system continues to be widely used, however, in certain formal and minor contexts, such as on clock faces, coins, in the year of construction on cornerstone inscriptions, and in generational suffixes (such as Louis XIV or William Howard Taft IV). According to the Royal Spanish Academy, in the Spanish language centuries must be written in Roman numerals, so "21st century" should be written as "Siglo XXI".